[SCSI] iscsi: redirect fix

From tomof@acm.org:

There is one more issue about Equallogic systems. They send
re-direction info with FIN. I think that the kernel module needs to
let iscsid to read data from the socket before killing it.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NAlex Aizman <itn780@yahoo.com>
Signed-off-by: NDmitry Yusupov <dmitry_yus@yahoo.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/iscsi_tcp.c

@@ -1237,8 +1237,9 @@ iscsi_tcp_state_change(struct sock *sk)
 	conn = (struct iscsi_conn*)sk->sk_user_data;
 	session = conn->session;
 
-	if (sk->sk_state == TCP_CLOSE_WAIT ||
-	    sk->sk_state == TCP_CLOSE) {
+	if ((sk->sk_state == TCP_CLOSE_WAIT ||
+	     sk->sk_state == TCP_CLOSE) &&
+	    !atomic_read(&sk->sk_rmem_alloc)) {
 		debug_tcp("iscsi_tcp_state_change: TCP_CLOSE|TCP_CLOSE_WAIT\n");
 		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
 	}