NFSv4: Initialise connection to the server in nfs4_alloc_client()

NFSv4: Initialise connection to the server in nfs4_alloc_client()

Origin: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/commit?id=ff4023d0194263a0827c954f623c314978cf7ddd
Bug-Debian-Security: https://security-tracker.debian.org/tracker/CVE-2021-38199

[ Upstream commit dd99e9f98fbf423ff6d365b37a98e8879170f17c ]

Set up the connection to the NFSv4 server in nfs4_alloc_client(), before
we've added the struct nfs_client to the net-namespace's nfs_client_list
so that a downed server won't cause other mounts to hang in the trunking
detection code.

Reported-by: Michael Wakabayashi <mwakabayashi@vmware.com>
Fixes: 5c6e5b60aae4 ("NFS: Fix an Oops in the pNFS files and flexfiles connection setup to the DS")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Gbp-Pq: Topic bugfix/all
Gbp-Pq: Name NFSv4-Initialise-connection-to-the-server-in-nfs4_al.patch