rapidio/rionet: fix deadlock on SMP

Fix deadlocking during concurrent receive and transmit operations on SMP
platforms caused by the use of incorrect lock: on transmit 'tx_lock'
spinlock should be used instead of 'lock' which is used for receive
operation.

This fix is applicable to kernel versions starting from v2.15.

Signed-off-by: Aurelien Jacquiot <a-jacquiot@ti.com>
Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Andre van Herk <andre.van.herk@prodrive-technologies.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/net/rionet.c b/drivers/net/rionet.c
index 01f08a7..e7034c5 100644
--- a/drivers/net/rionet.c
+++ b/drivers/net/rionet.c
@@ -280,7 +280,7 @@
 	struct net_device *ndev = dev_id;
 	struct rionet_private *rnet = netdev_priv(ndev);
 
-	spin_lock(&rnet->lock);
+	spin_lock(&rnet->tx_lock);
 
 	if (netif_msg_intr(rnet))
 		printk(KERN_INFO
@@ -299,7 +299,7 @@
 	if (rnet->tx_cnt < RIONET_TX_RING_SIZE)
 		netif_wake_queue(ndev);
 
-	spin_unlock(&rnet->lock);
+	spin_unlock(&rnet->tx_lock);
 }
 
 static int rionet_open(struct net_device *ndev)