Fix Symbian Builds

Core/WaveFile.cpp

@@ -1,7 +1,7 @@
 // Copyright 2008 Dolphin Emulator Project
 // Licensed under GPLv2+
 // Refer to the license.txt file included.
-
+#ifndef MOBILE_DEVICE
 #include <string>
 
 #include "Core/WaveFile.h"
@@ -114,3 +114,4 @@ void WaveFileWriter::AddStereoSamples(const short* sample_data, u32 count)
 	file.WriteBytes(sample_data, count * 4);
 	audio_size += count * 4;
 }
+#endif