Add format specification to output file names

This change facilitates running ApmTest.VerifyDebugDumpInt and
ApmTest.VerifyDebugDumpFloat in parallel, since they are not writing
to the same files any longer.

R=andrew@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/10989004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@5829 4adac7df-926f-26a2-2b94-8c16560cd09d
1 file changed