omxvideodec: log info about frame before releasing it
omxvideodec: log info about frame before releasing it

gst_video_decoder_release_frame() takes ownership of the frame and will
destroy it. So we should no longer use it after calling it.

https://bugzilla.gnome.org/show_bug.cgi?id=787628

GStreamer/gst-omx,GStreamer/gst-omx,GStreamer/gst-omx