cifs: double lock in cifs_reconnect_tcon()

This lock was supposed to be an unlock.

Fixes: 6cc041e9 ("cifs: avoid races in parallel reconnects in smb1")
Signed-off-by: Dan Carpenter <error27@gmail.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>