RDMA/cxgb3: Check return of kmalloc() in iwch_register_device()

Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
[ Also remove cast from void * return of kmalloc() as suggested by  
  Jesper Juhl <jesper.juhl@gmail.com>. ]
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/hw/cxgb3/iwch_provider.c

@@ -1163,9 +1163,10 @@ int iwch_register_device(struct iwch_dev *dev)
 	dev->ibdev.post_recv = iwch_post_receive;
 
 
-	dev->ibdev.iwcm =
-	    (struct iw_cm_verbs *) kmalloc(sizeof(struct iw_cm_verbs),
-					   GFP_KERNEL);
+	dev->ibdev.iwcm = kmalloc(sizeof(struct iw_cm_verbs), GFP_KERNEL);
+	if (!dev->ibdev.iwcm)
+		return -ENOMEM;
+
 	dev->ibdev.iwcm->connect = iwch_connect;
 	dev->ibdev.iwcm->accept = iwch_accept_cr;
 	dev->ibdev.iwcm->reject = iwch_reject_cr;