Include cerrno for errno; fixes clang compilation error

AMDmi3 · AMDmi3 · commit cfbec1f47014 · 2015-06-02T04:36:30.000+03:00
diff --git a/src/audio/sfx_manager.cpp b/src/audio/sfx_manager.cpp
@@ -28,6 +28,7 @@
 #include <pthread.h>
 #include <stdexcept>
 #include <algorithm>
+#include <cerrno>
 #include <map>
 
 #include <stdio.h>
