lavfi/anull: remove redundant lines

Signed-off-by: Paul B Mahol <onemda@gmail.com>
lavfi: use ceil right shift for chroma width/height.

This should fix several issues with odd dimensions inputs.

lut, vflip, pad and crop video filters also need to be checked for such
issues. It's possible sws is also affected.
lavfi: avectorscope filter

Signed-off-by: Paul B Mahol <onemda@gmail.com>
lavfi/select: set forgotten VAR_PICT_TYPE_BI

Signed-off-by: Paul B Mahol <onemda@gmail.com>
sws/output/yuv2gbrp_full_X_c(): silence warning about uninitialized variable

clang did not show this one, so i missed it in the last batch

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
sws: add casts to silence pointer type mismatch warnings

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>