cifs: return a single-use cfid if we did not get a lease

cifs: return a single-use cfid if we did not get a lease

If we did not get a lease we can still return a single use cfid to the caller.
The cfid will not have has_lease set and will thus not be shared with any
other concurrent users and will be freed immediately when the caller
drops the handle.

This avoids extra roundtrips for servers that do not support directory leases
where they would first fail to get a cfid with a lease and then fallback
to try a normal SMB2_open()

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Cc: stable@vger.kernel.org
Reviewed-by: Bharath SM <bharathsm@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>