bnx2fc: check IS_ERR() instead of NULL

The bnx2fc_if_create() function returns NULL on failure, it never
returns an error pointer.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Chad Dupuis <chad.dupuis@qlogic.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/scsi/bnx2fc/bnx2fc_fcoe.c

@@ -1081,7 +1081,7 @@ static int bnx2fc_vport_create(struct fc_vport *vport, bool disabled)
 	mutex_unlock(&bnx2fc_dev_lock);
 	rtnl_unlock();
 
-	if (IS_ERR(vn_port)) {
+	if (!vn_port) {
 		printk(KERN_ERR PFX "bnx2fc_vport_create (%s) failed\n",
 			netdev->name);
 		return -EIO;