h264_nal: fix parsing of the end of SPS and PPS NAL units
h264_nal: fix parsing of the end of SPS and PPS NAL units

SPS and PPS NAL units always start with 0x00000001 and finish with 0x000000,
0x000001 or the end of the bytestream.

xkfz007/vlc,shyamalschandra/vlc,vlc-mirror/vlc,xkfz007/vlc,vlc-mirror/vlc,vlc-mirror/vlc,shyamalschandra/vlc,shyamalschandra/vlc,xkfz007/vlc,shyamalschandra/vlc,vlc-mirror/vlc,vlc-mirror/vlc,shyamalschandra/vlc,shyamalschandra/vlc,xkfz007/vlc,xkfz007/vlc,vlc-mirror/vlc,vlc-mirror/vlc,shyamalschandra/vlc,xkfz007/vlc,xkfz007/vlc