avfilter/vf_mp: remove incorrect usage of AVFrame.type

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avformat/id3v2: Fix "warning: unused variable uncompressed_buffer_size" if zlib is unavailable

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
ffmpeg: Clean up if filter initialisation failed to avoid a memleak.

Fixes ticket #3858.

Reviewed-by: Nicolas George
lavf/rtpdec_hevc: Fix compilation with -DDEBUG.