Before return, should free the xid, otherwise, the
xid will be leaked.

Fixes: d70e9fa5 ("cifs: try opening channels after mounting")
Reviewed-by: NPaulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: NZhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>