cifs: Do not use the original cruid when following DFS links for multiuser mounts

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=213565



cruid should only be used for the initial mount and after this we should use the current
users credentials.
Ignore the original cruid mount argument when creating a new context for a multiuser mount
following a DFS link.

Fixes: 24e0a1ef ("cifs: switch to new mount api")
Cc: stable@vger.kernel.org # 5.11+
Reported-by: Xiaoli Feng <xifeng@redhat.com>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>