Rename _t struct types in audio_processing.

_t names are reserved in POSIX.

R=bjornv@webrtc.org
BUG=162

Review URL: https://webrtc-codereview.appspot.com/34509005

git-svn-id: http://webrtc.googlecode.com/svn/trunk@7943 4adac7df-926f-26a2-2b94-8c16560cd09d

webrtc/modules/audio_processing/gain_control_impl.cc

@@ -323,7 +323,7 @@ int GainControlImpl::InitializeHandle(void* handle) const {
 }
 
 int GainControlImpl::ConfigureHandle(void* handle) const {
-  WebRtcAgc_config_t config;
+  WebRtcAgcConfig config;
   // TODO(ajm): Flip the sign here (since AGC expects a positive value) if we
   //            change the interface.
   //assert(target_level_dbfs_ <= 0);