[N-Rage] fixed ARRAYSIZE() #define when missing headers

The old code only cared about if the macro was already defined (then #undef and re-define it).  If it was NOT already defined, it just ignored the problem and causes unresolved compile-time symbols.

Source/nragev20/commonIncludes.h

@@ -42,7 +42,8 @@
 
 #ifdef ARRAYSIZE
 #undef ARRAYSIZE
-#define ARRAYSIZE( array ) (sizeof(array) / sizeof(array[0]))
 #endif //ARRAYSIZE
 
+#define ARRAYSIZE(array)        (sizeof(array) / sizeof((array)[0]))
+
 #endif // #ifndef _COMMONINCLUDES_H_