SMB3: avoid confusing warning message on mount to Azure

Mounts to Azure cause an unneeded warning message in dmesg
   "CIFS: VFS: parse_server_interfaces: incomplete interface info"

Azure rounds up the size (by 8 additional bytes, to a
16 byte boundary) of the structure returned on the query
of the server interfaces at mount time.  This is permissible
even though different than other servers so do not log a warning
if query network interfaces response is only rounded up by 8
bytes or fewer.

CC: Stable <stable@vger.kernel.org>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>