remove unnecessary parentheses from expand()

Not sure why I forgot to do this, but here is a small bit of tidying up of some leftover parentheses from the memlist macro removal. The parentheses are just noise and should go.

Cheers,
Bill

===== mm/page_alloc.c 1.67 vs edited =====

@@ -173,7 +173,7 @@
 		area--;
 		high--;
 		size >>= 1;
-		list_add(&(page)->list, &(area)->free_list);
+		list_add(&page->list, &area->free_list);
 		MARK_USED(index, high, area);
 		index += size;
 		page += size;