Enable proper display of elapsed time when paused with VAAPI.

Make sure av_pause_frame is updated so that the player can pick up the
current frame number while paused.  Refs #10962

mythtv/libs/libmythtv/videoout_openglvaapi.cpp

@@ -247,6 +247,7 @@ void VideoOutputOpenGLVAAPI::UpdatePauseFrame(int64_t &disp_timecode)
     if (vbuffers.Size(kVideoBuffer_used))
     {
         VideoFrame *frame = vbuffers.Head(kVideoBuffer_used);
+        CopyFrame(&av_pause_frame, frame);
         m_pauseBuffer = frame->buf;
         disp_timecode = frame->disp_timecode;
     }