Convert obvious places to deactivate_locked_super()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index faa44f9..e9f7a75 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -2055,8 +2055,7 @@
 	return 0;
 
 out_deact:
-	up_write(&sb->s_umount);
-	deactivate_super(sb);
+	deactivate_locked_super(sb);
 out_close:
 	ubi_close_volume(ubi);
 	return err;