mm, mempolicy: remove duplicate code

Remove some duplicate code and simplify alloc_pages_vma().  No functional
change.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/mempolicy.c

@@ -1907,7 +1907,6 @@ alloc_pages_vma(gfp_t gfp, int order, struct vm_area_struct *vma,
 		unsigned long addr, int node)
 {
 	struct mempolicy *pol;
-	struct zonelist *zl;
 	struct page *page;
 	unsigned int cpuset_mems_cookie;
 
@@ -1926,23 +1925,11 @@ alloc_pages_vma(gfp_t gfp, int order, struct vm_area_struct *vma,
 
 		return page;
 	}
-	zl = policy_zonelist(gfp, pol, node);
-	if (unlikely(mpol_needs_cond_ref(pol))) {
-		/*
-		 * slow path: ref counted shared policy
-		 */
-		struct page *page =  __alloc_pages_nodemask(gfp, order,
-						zl, policy_nodemask(gfp, pol));
-		__mpol_put(pol);
-		if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page))
-			goto retry_cpuset;
-		return page;
-	}
-	/*
-	 * fast path:  default or task policy
-	 */
-	page = __alloc_pages_nodemask(gfp, order, zl,
+	page = __alloc_pages_nodemask(gfp, order,
+				      policy_zonelist(gfp, pol, node),
 				      policy_nodemask(gfp, pol));
+	if (unlikely(mpol_needs_cond_ref(pol)))
+		__mpol_put(pol);
 	if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page))
 		goto retry_cpuset;
 	return page;