v4l2videodec: needn't unref caps after unref query.

https://bugzilla.gnome.org/show_bug.cgi?id=752962

UpStream Status: Pending
diff --git a/sys/v4l2/gstv4l2videodec.c b/sys/v4l2/gstv4l2videodec.c
index e7d679d..6f7014e 100644
--- a/sys/v4l2/gstv4l2videodec.c
+++ b/sys/v4l2/gstv4l2videodec.c
@@ -267,7 +267,6 @@
         GstQuery *query = gst_query_new_allocation (caps, FALSE);
         gst_pad_peer_query (decoder->srcpad, query);
         gst_query_unref (query);
-        gst_caps_unref (caps);
       }
     }