cifs: pull freeing mountdata/dropping nls/freeing cifs_sb into cifs_umount()

all callers of cifs_umount() proceed to do the same thing; pull it into
cifs_umount() itself.

Acked-by: Pavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/cifs/connect.c

@@ -3362,6 +3362,9 @@ cifs_umount(struct cifs_sb_info *cifs_sb)
 	spin_unlock(&cifs_sb->tlink_tree_lock);
 
 	bdi_destroy(&cifs_sb->bdi);
+	kfree(cifs_sb->mountdata);
+	unload_nls(cifs_sb->local_nls);
+	kfree(cifs_sb);
 }
 
 int cifs_negotiate_protocol(unsigned int xid, struct cifs_ses *ses)