demux: avi: missing initializers

really unlikely (malloc fails)
cid #1049010 #1049009 #1049008 #1049007 #1049006
codec: vorbix: max channels is 8

fix cid #1048883
stream_filter: smooth: fix negative array access

cid #1048853
access: cdda: fix resource leak

cid 403219
ioctl isn't released
transform: make filter work with chain where format change permitted

Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>
Win32: the dimensions of the unclipped source rectangle should be the original format of the video

Fix #10886