decoder: fix NULL dereference when pausing packetizer
decoder: fix NULL dereference when pausing packetizer

DecoderProcess() can only be used with the decoder, not the packetizer.
Inline DecoderFlush() to fix the issue.

xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc