cnic: Use proper ulp_ops for per device operations.

For per device operations, cnic needs to dereference the RCU protected
cp->ulp_ops instead of the global cnic_ulp_tbl.  In 2 locations,
cnic_send_nlmsg() and cnic_copy_ulp_stats(), it was referencing the
global table.  If the device has been unregistered and these functions
are still being called (very unlikely scenarios), it could lead to NULL
pointer dereference.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/broadcom/cnic.c b/drivers/net/ethernet/broadcom/cnic.c
index fcf9105a5..2cb2482 100644
--- a/drivers/net/ethernet/broadcom/cnic.c
+++ b/drivers/net/ethernet/broadcom/cnic.c
@@ -342,7 +342,7 @@
 	while (retry < 3) {
 		rc = 0;
 		rcu_read_lock();
-		ulp_ops = rcu_dereference(cnic_ulp_tbl[CNIC_ULP_ISCSI]);
+		ulp_ops = rcu_dereference(cp->ulp_ops[CNIC_ULP_ISCSI]);
 		if (ulp_ops)
 			rc = ulp_ops->iscsi_nl_send_msg(
 				cp->ulp_handle[CNIC_ULP_ISCSI],
@@ -3244,7 +3244,8 @@
 	int rc;
 
 	mutex_lock(&cnic_lock);
-	ulp_ops = cnic_ulp_tbl_prot(ulp_type);
+	ulp_ops = rcu_dereference_protected(cp->ulp_ops[ulp_type],
+					    lockdep_is_held(&cnic_lock));
 	if (ulp_ops && ulp_ops->cnic_get_stats)
 		rc = ulp_ops->cnic_get_stats(cp->ulp_handle[ulp_type]);
 	else