SMB1 already has support to read attributes. This adds similar support
to SMB2+.

With this patch, tools such as 'getfattr' will now work with SMB2+ shares.

RH-bz: 1110709
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>