ceph: delete an unnecessary return statement in update_dentry_lease()

The script "checkpatch.pl" pointed information out like the following.

WARNING: void function return statements are not generally useful

Thus remove such a statement in the affected function.
Signed-off-by: NMarkus Elfring <elfring@users.sourceforge.net>
Reviewed-by: NYan, Zheng <zyan@redhat.com>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

fs/ceph/inode.c

@@ -1067,7 +1067,6 @@ static void update_dentry_lease(struct dentry *dentry,
 	spin_unlock(&dentry->d_lock);
 	if (old_lease_session)
 		ceph_put_mds_session(old_lease_session);
-	return;
 }
 
 /*