[SCSI] scsi_transport_sas: make write attrs writeable

A couple write attributes in sas transport layer have a small
bug that prevents them from being written to.  Those
attributes are the link_reset and write_reset.  This is due
the store field being set to NULL.
Signed-off-by: Eric Moore <Eric.Moore@lsil.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/scsi_transport_sas.c

@@ -978,7 +978,6 @@ static int sas_user_scan(struct Scsi_Host *shost, uint channel,
 #define SETUP_TEMPLATE(attrb, field, perm, test)				\
 	i->private_##attrb[count] = class_device_attr_##field;		\
 	i->private_##attrb[count].attr.mode = perm;			\
-	i->private_##attrb[count].store = NULL;				\
 	i->attrb[count] = &i->private_##attrb[count];			\
 	if (test)							\
 		count++