VideoWriter error handling cleanup.
VideoWriter error handling cleanup.

svn path=/trunk/libavg/; revision=6781

hoodie/libavg,yyd01245/libavg,th3infinity/libavg,libavg/libavg,scotty007/libavg,th3infinity/libavg,hoodie/libavg,hoodie/libavg,libavg/libavg,yyd01245/libavg,yyd01245/libavg,th3infinity/libavg,scotty007/libavg,scotty007/libavg,scotty007/libavg,yyd01245/libavg,libavg/libavg,th3infinity/libavg,libavg/libavg,hoodie/libavg