Enable format warnings under MinGW

code/game/bg_lib.h

@@ -94,7 +94,7 @@ int atoi( const char *string );
 int _atoi( const char **stringPtr );
 long strtol( const char *nptr, char **endptr, int base );
 
-int Q_vsnprintf( char *buffer, size_t length, const char *fmt, va_list argptr );
+int Q_vsnprintf( char *buffer, size_t length, const char *fmt, va_list argptr ) Q_PRINTF_FUNC(3, 0);
 
 int sscanf( const char *buffer, const char *fmt, ... ) Q_SCANF_FUNC(2, 3);