Fixed threaded RGBA video decoding.
Fixed threaded RGBA video decoding.

svn path=/trunk/libavg/; revision=2626

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