Update srtp error value in channel unittests.
Update srtp error value in channel unittests.

TBR=ronghuawu@webrtc.org

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

Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 4d3e8b8c1b9c037a363772f30d1ffa4c6f60699c

sippet/talk,sippet/talk,sippet/talk,sippet/talk,sippet/talk