Change sprintf use in talk samples to snprintf

BUG=2301
R=juberti@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/41579004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@8128 4adac7df-926f-26a2-2b94-8c16560cd09d
2 files changed