[SCSI] libiscsi, iscsi_tcp: add device support

This patch adds logical unit reset support. This should work for ib_iser,
but I have not finished testing that driver so it is not hooked in yet.

This patch also temporarily reverts the iscsi_tcp r2t write out patch.
That code is completely rewritten in this patchset.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

drivers/infiniband/ulp/iser/iscsi_iser.c

@@ -220,12 +220,6 @@ iscsi_iser_ctask_xmit(struct iscsi_conn *conn,
 	debug_scsi("ctask deq [cid %d itt 0x%x]\n",
 		   conn->id, ctask->itt);
 
-	/*
-	 * serialize with TMF AbortTask
-	 */
-	if (ctask->mtask)
-		return error;
-
 	/* Send the cmd PDU */
 	if (!iser_ctask->command_sent) {
 		error = iser_send_command(conn, ctask);