Include files from webrtc/.. paths in common_audio/

BUG=1662
R=tina.legrand@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/1535005

git-svn-id: http://webrtc.googlecode.com/svn/trunk@4107 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/common_audio/signal_processing/complex_fft.c b/webrtc/common_audio/signal_processing/complex_fft.c
index fe89ae3..81c7857 100644
--- a/webrtc/common_audio/signal_processing/complex_fft.c
+++ b/webrtc/common_audio/signal_processing/complex_fft.c
@@ -15,7 +15,7 @@
  *
  */
 
-#include "signal_processing_library.h"
+#include "webrtc/common_audio/signal_processing/include/signal_processing_library.h"
 
 #define CFFTSFT 14
 #define CFFTRND 1