Merge remote-tracking branch 'qatar/master'

* qatar/master:
  swscale: fix byte overreads in SSE-optimized hscale().
  matroskadec: fix typo.
  matroskadec: bail on parsing of incorrect seek index segments

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

diff --cc libavformat/matroskadec.c
Simple merge

diff --cc libswscale/utils.c
Simple merge