mm: vma_adjust: remove superfluous check for next not NULL

If next would be NULL we couldn't reach such code path.

Link: http://lkml.kernel.org/r/1474309513-20313-2-git-send-email-aarcange@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Jan Vorlicek <janvorli@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/mmap.c

@@ -706,7 +706,7 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
 			 * If next doesn't have anon_vma, import from vma after
 			 * next, if the vma overlaps with it.
 			 */
-			if (remove_next == 2 && next && !next->anon_vma)
+			if (remove_next == 2 && !next->anon_vma)
 				exporter = next->vm_next;
 
 		} else if (end > next->vm_start) {