Update srtp error value in channel unittests.

TBR=ronghuawu@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/2053004

git-svn-id: http://webrtc.googlecode.com/svn/trunk/talk@4557 4adac7df-926f-26a2-2b94-8c16560cd09d
1 file changed