fixed VC issue with SQ_UNUSED_ARG

include/squirrel.h

@@ -400,7 +400,7 @@ SQUIRREL_API void sq_setnativedebughook(HSQUIRRELVM v,SQDEBUGHOOK hook);
 #ifdef __GNUC__
 # define SQ_UNUSED_ARG(x) __attribute__((unused)) x
 #else
-# define SQ_UNUSED_ARG(x)
+# define SQ_UNUSED_ARG(x) 
 #endif
 
 #ifdef __cplusplus