matroskadec: favor av_freep()

av_freep() is safer as it zeros the pointer

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
matroskadec: fix memleak of pkt_data

Fixes: CID1026767
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avformat/network: check the return value from setsockopt()

Fixes: CID1026742
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>