mmap: EINVAL not ENOMEM when rejecting VM_GROWS

Currently error is -ENOMEM when rejecting VM_GROWSDOWN|VM_GROWSUP
from shared anonymous: hoist the file case's -EINVAL up for both.

Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/mmap.c

@@ -1266,8 +1266,9 @@ munmap_back:
 	vma->vm_pgoff = pgoff;
 	INIT_LIST_HEAD(&vma->anon_vma_chain);
 
+	error = -EINVAL;	/* when rejecting VM_GROWSDOWN|VM_GROWSUP */
+
 	if (file) {
-		error = -EINVAL;
 		if (vm_flags & (VM_GROWSDOWN|VM_GROWSUP))
 			goto free_vma;
 		if (vm_flags & VM_DENYWRITE) {