gl: Also don't leak floating references to elements set via properties

Fixup for 58ac815eae6ed468d1db60a54a1bd34d6324c28c. Floating references
are such a mess.
diff --git a/ext/gl/gstglfilterbin.c b/ext/gl/gstglfilterbin.c
index f6f7856..338f22b 100644
--- a/ext/gl/gstglfilterbin.c
+++ b/ext/gl/gstglfilterbin.c
@@ -173,7 +173,7 @@
 }
 
 /*
- * @filter: (transfer full):
+ * @filter: (transfer floating):
  */
 static gboolean
 gst_gl_filter_bin_set_filter (GstGLFilterBin * self, GstElement * filter)
@@ -189,10 +189,10 @@
   }
   self->filter = filter;
 
-  if (filter && g_object_is_floating (filter))
-    gst_object_ref_sink (filter);
+  gst_object_ref_sink (filter);
 
   if (filter && !_connect_filter_element (self)) {
+    gst_object_unref (self->filter);
     self->filter = NULL;
     return FALSE;
   }
@@ -204,8 +204,7 @@
 gst_gl_filter_bin_finish_init_with_element (GstGLFilterBin * self,
     GstElement * element)
 {
-  if (!gst_gl_filter_bin_set_filter (self, element))
-    gst_object_unref (element);
+  gst_gl_filter_bin_set_filter (self, element);
 }
 
 void
@@ -245,7 +244,7 @@
 
   switch (prop_id) {
     case PROP_FILTER:
-      gst_gl_filter_bin_set_filter (self, g_value_dup_object (value));
+      gst_gl_filter_bin_set_filter (self, g_value_get_object (value));
       break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
diff --git a/ext/gl/gstglmixerbin.c b/ext/gl/gstglmixerbin.c
index 0c52c29..b30e6a8 100644
--- a/ext/gl/gstglmixerbin.c
+++ b/ext/gl/gstglmixerbin.c
@@ -399,7 +399,7 @@
 }
 
 /*
- * @mixer: (transfer full):
+ * @mixer: (transfer floating):
  */
 static gboolean
 gst_gl_mixer_bin_set_mixer (GstGLMixerBin * self, GstElement * mixer)
@@ -415,10 +415,10 @@
   }
   self->mixer = mixer;
 
-  if (mixer && g_object_is_floating (mixer))
-    gst_object_ref_sink (mixer);
+  gst_object_ref_sink (mixer);
 
   if (mixer && !_connect_mixer_element (self)) {
+    gst_object_unref (self->mixer);
     self->mixer = NULL;
     return FALSE;
   }
@@ -430,8 +430,7 @@
 gst_gl_mixer_bin_finish_init_with_element (GstGLMixerBin * self,
     GstElement * element)
 {
-  if (!gst_gl_mixer_bin_set_mixer (self, element))
-    gst_object_unref (element);
+  gst_gl_mixer_bin_set_mixer (self, element);
 }
 
 void
@@ -473,7 +472,7 @@
   switch (prop_id) {
     case PROP_MIXER:
     {
-      GstElement *mixer = g_value_dup_object (value);
+      GstElement *mixer = g_value_get_object (value);
       /* FIXME: deal with replacing a mixer */
       g_return_if_fail (!self->mixer || (self->mixer == mixer));
       gst_gl_mixer_bin_set_mixer (self, mixer);
diff --git a/ext/gl/gstglsinkbin.c b/ext/gl/gstglsinkbin.c
index a3093d0..02511f5 100644
--- a/ext/gl/gstglsinkbin.c
+++ b/ext/gl/gstglsinkbin.c
@@ -307,10 +307,10 @@
   }
   self->sink = sink;
 
-  if (sink && g_object_is_floating (sink))
-    gst_object_ref_sink (sink);
+  gst_object_ref_sink (sink);
 
   if (sink && !_connect_sink_element (self)) {
+    gst_object_unref (self->sink);
     self->sink = NULL;
     return FALSE;
   }
@@ -322,8 +322,7 @@
 gst_gl_sink_bin_finish_init_with_element (GstGLSinkBin * self,
     GstElement * element)
 {
-  if (!gst_gl_sink_bin_set_sink (self, element))
-    gst_object_unref (element);
+  gst_gl_sink_bin_set_sink (self, element);
 }
 
 void
@@ -347,7 +346,7 @@
 
   switch (prop_id) {
     case PROP_SINK:
-      gst_gl_sink_bin_set_sink (self, g_value_dup_object (value));
+      gst_gl_sink_bin_set_sink (self, g_value_get_object (value));
       break;
     case PROP_CONTRAST:
     case PROP_BRIGHTNESS:
diff --git a/ext/gl/gstglsrcbin.c b/ext/gl/gstglsrcbin.c
index bae46a0..e1004d2 100644
--- a/ext/gl/gstglsrcbin.c
+++ b/ext/gl/gstglsrcbin.c
@@ -165,7 +165,7 @@
 }
 
 /*
- * @src: (transfer full):
+ * @src: (transfer floating):
  */
 static gboolean
 gst_gl_src_bin_set_src (GstGLSrcBin * self, GstElement * src)
@@ -181,10 +181,10 @@
   }
   self->src = src;
 
-  if (src && g_object_is_floating (src))
-    gst_object_ref_sink (src);
+  gst_object_ref_sink (src);
 
   if (src && !_connect_src_element (self)) {
+    gst_object_unref (self->src);
     self->src = NULL;
     return FALSE;
   }
@@ -196,8 +196,7 @@
 gst_gl_src_bin_finish_init_with_element (GstGLSrcBin * self,
     GstElement * element)
 {
-  if (!gst_gl_src_bin_set_src (self, element))
-    gst_object_unref (self->src);
+  gst_gl_src_bin_set_src (self, element);
 }
 
 void
@@ -221,7 +220,7 @@
 
   switch (prop_id) {
     case PROP_SRC:
-      gst_gl_src_bin_set_src (self, g_value_dup_object (value));
+      gst_gl_src_bin_set_src (self, g_value_get_object (value));
       break;
     default:
       if (self->src)