omxvideoenc: factor out gst_omx_video_enc_pause_loop()
omxvideoenc: factor out gst_omx_video_enc_pause_loop()

No semantic change. I'm going to use it in more failure cases.

https://bugzilla.gnome.org/show_bug.cgi?id=796207

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