[CIFS] Fix sparse warning

Also update CHANGES file
Signed-off-by: Steve French <sfrench@us.ibm.com>

fs/cifs/CHANGES

+Version 1.61
+------------
+Fix append problem to Samba servers (files opened with O_APPEND could
+have duplicated data). Fix oops in cifs_lookup. Workaround problem
+mounting to OS/400 Netserve. Fix oops in cifs_get_tcp_session.
+Disable use of server inode numbers when server only
+partially supports them (e.g. for one server querying inode numbers on
+FindFirst fails but QPathInfo queries works).
+
 Version 1.60
 -------------
 Fix memory leak in reconnect.  Fix oops in DFS mount error path.

fs/cifs/dir.c

@@ -643,7 +643,7 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
 	 */
 	if (nd && (nd->flags & LOOKUP_EXCL)) {
 		d_instantiate(direntry, NULL);
-		return 0;
+		return NULL;
 	}
 
 	/* can not grab the rename sem here since it would