mm/memory.c: remove unused code from do_wp_page()

page_mkwrite is initalized with zero and only set once, from that point
exists no way to get to the oom or oom_free_new labels.

[akpm@linux-foundation.org: cleanup]
Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memory.c

@@ -2780,13 +2780,8 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
 oom_free_new:
 	page_cache_release(new_page);
 oom:
-	if (old_page) {
-		if (page_mkwrite) {
-			unlock_page(old_page);
+	if (old_page)
 		page_cache_release(old_page);
-		}
-		page_cache_release(old_page);
-	}
 	return VM_FAULT_OOM;
 
 unwritable_page: