cifs: Fix lost destroy smbd connection when MR allocate failed

[ Upstream commit e9d3401d95d62a9531082cd2453ed42f2740e3fd ]

If the MR allocate failed, the smb direct connection info is NULL,
then smbd_destroy() will directly return, then the connection info
will be leaked.

Let's set the smb direct connection info to the server before call
smbd_destroy().

Fixes: c7398583 ("CIFS: SMBD: Implement RDMA memory registration")
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Acked-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: David Howells <dhowells@redhat.com>
Reviewed-by: Tom Talpey <tom@talpey.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>