correcting syntax error

mem/ll_malloc.c

@@ -970,7 +970,7 @@ void sfm_status(struct sfm_block* qm)
 	unsigned long size;
 	int k;
 
-#warning ll_status doesn't work (might crash if used)
+#warning "ll_status doesn't work (might crash if used)"
 
 	LOG(memlog, "sfm_status (%p):\n", qm);
 	if (!qm) return;