cifs: remove unneeded return statement

[ Upstream commit a3f763fd ]

Return statement was not needed at end of cifs_chan_update_iface

Suggested-by: Christophe Jaillet <christophe.jaillet@wanadoo.fr>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>