Fixes: The warnings from CID1598553 Uninitialized scalar variable

Passing partly initialized structs is ugly and asking for hard to rieproduce bugs,
The uninitialized fields where not used
Reviewed-by: "Xiang, Haihao" <haihao.xiang-at-intel.com@ffmpeg.org>
Sponsored-by: Sovereign Tech Fund
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>