gst-ffmpeg: fix for Security Advisory CVE-2014-2099

gst-ffmpeg: fix for Security Advisory CVE-2014-2099

The msrle_decode_frame function in libavcodec/msrle.c in FFmpeg before
2.1.4 does not properly calculate line sizes, which allows remote
attackers to cause a denial of service (out-of-bounds array access) or
possibly have unspecified other impact via crafted Microsoft RLE video
data.

http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2014-2099

Signed-off-by: Yue Tao <Yue.Tao@windriver.com>
Signed-off-by: Roy Li <rongqing.li@windriver.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>