xvimage: Fix symbol redefine build error

https://bugzilla.gnome.org/show_bug.cgi?id=796827
diff --git a/sys/xvimage/xvimage.c b/sys/xvimage/xvimage.c
index 66bd180..e0295bc 100644
--- a/sys/xvimage/xvimage.c
+++ b/sys/xvimage/xvimage.c
@@ -26,7 +26,6 @@
 GST_DEBUG_CATEGORY (gst_debug_xv_context);
 GST_DEBUG_CATEGORY (gst_debug_xv_image_pool);
 GST_DEBUG_CATEGORY (gst_debug_xv_image_sink);
-GST_DEBUG_CATEGORY (CAT_PERFORMANCE);
 
 static gboolean
 plugin_init (GstPlugin * plugin)
@@ -42,8 +41,6 @@
   GST_DEBUG_CATEGORY_INIT (gst_debug_xv_image_pool, "xvimagepool", 0,
       "xvimagepool object");
 
-  GST_DEBUG_CATEGORY_GET (CAT_PERFORMANCE, "GST_PERFORMANCE");
-
   return TRUE;
 }
 
diff --git a/sys/xvimage/xvimagesink.c b/sys/xvimage/xvimagesink.c
index 322117c..50d9dd2 100644
--- a/sys/xvimage/xvimagesink.c
+++ b/sys/xvimage/xvimagesink.c
@@ -133,8 +133,8 @@
 #include <X11/XKBlib.h>
 
 GST_DEBUG_CATEGORY_EXTERN (gst_debug_xv_image_sink);
-GST_DEBUG_CATEGORY_EXTERN (CAT_PERFORMANCE);
 #define GST_CAT_DEFAULT gst_debug_xv_image_sink
+GST_DEBUG_CATEGORY_STATIC (GST_CAT_PERFORMANCE);
 
 typedef struct
 {
@@ -963,7 +963,7 @@
     if (res != GST_FLOW_OK)
       goto no_buffer;
 
-    GST_CAT_LOG_OBJECT (CAT_PERFORMANCE, xvimagesink,
+    GST_CAT_LOG_OBJECT (GST_CAT_PERFORMANCE, xvimagesink,
         "slow copy buffer %p into bufferpool buffer %p", buf, to_put);
 
     if (!gst_video_frame_map (&src, &xvimagesink->info, buf, GST_MAP_READ))
@@ -2045,4 +2045,6 @@
 
   videosink_class->show_frame =
       GST_DEBUG_FUNCPTR (gst_xv_image_sink_show_frame);
+
+  GST_DEBUG_CATEGORY_GET (GST_CAT_PERFORMANCE, "GST_PERFORMANCE");
 }