Attempt to move mixer to audio common, it's a bit more complicated than I expected

so please check I didn't break anything in hle



git-svn-id: https://dolphin-emu.googlecode.com/svn/trunk@2756 8ced0084-cf51-0410-be5f-012b33b47a6e

Source/Plugins/Plugin_DSP_LLE-testing/Src/Logging/Logging.h

@@ -15,9 +15,9 @@
 // Official SVN repository and contact information can be found at
 // http://code.google.com/p/dolphin-emu/
 
-
-#ifdef _WIN32
+#ifndef LOGGING_H
+#define LOGGING_H
 
 void Logging();
 
-#endif
+#endif