Merge commit 'b03b2d86'

* commit 'b03b2d86':
  buffersrc: avoid using AV_PIX_FMT_NB

Conflicts:
	libavfilter/buffersrc.c

No change as AV_PIX_FMT_NB was not used by our buffersrc.c
See: 0d58bbb2Merged-by: Michael Niedermayer <michaelni@gmx.at>