NetEq4: Removing templatization for AudioMultiVector

This saves approx 6% runtime for neteq4_speed_test.
$ time out/Release/neteq4_speed_test --runtime_ms=50000000

BUG=1363
R=minyue@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/2320006

git-svn-id: http://webrtc.googlecode.com/svn/trunk@4885 4adac7df-926f-26a2-2b94-8c16560cd09d

webrtc/modules/audio_coding/neteq4/comfort_noise.cc

@@ -50,7 +50,7 @@ int ComfortNoise::UpdateParameters(Packet* packet) {
 }
 
 int ComfortNoise::Generate(size_t requested_length,
-                           AudioMultiVector<int16_t>* output) {
+                           AudioMultiVector* output) {
   // TODO(hlundin): Change to an enumerator and skip assert.
   assert(fs_hz_ == 8000 || fs_hz_ == 16000 || fs_hz_ ==  32000 ||
          fs_hz_ == 48000);