arcnet: Remove pointer comparisons to NULL

Use direct tests of pointer instead.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>

drivers/net/arcnet/arc-rawmode.c

@@ -97,7 +97,7 @@ static void rx(struct net_device *dev, int bufnum,
 		ofs = 256 - length;
 
 	skb = alloc_skb(length + ARC_HDR_SIZE, GFP_ATOMIC);
-	if (skb == NULL) {
+	if (!skb) {
 		dev->stats.rx_dropped++;
 		return;
 	}

drivers/net/arcnet/capmode.c

@@ -56,7 +56,7 @@ static void rx(struct net_device *dev, int bufnum,
 		ofs = 256 - length;
 
 	skb = alloc_skb(length + ARC_HDR_SIZE + sizeof(int), GFP_ATOMIC);
-	if (skb == NULL) {
+	if (!skb) {
 		dev->stats.rx_dropped++;
 		return;
 	}
@@ -196,7 +196,7 @@ static int ack_tx(struct net_device *dev, int acked)
 
 	/* Now alloc a skb to send back up through the layers: */
 	ackskb = alloc_skb(length + ARC_HDR_SIZE, GFP_ATOMIC);
-	if (ackskb == NULL)
+	if (!ackskb)
 		goto free_outskb;
 
 	skb_put(ackskb, length + ARC_HDR_SIZE);

drivers/net/arcnet/rfc1051.c

@@ -133,7 +133,7 @@ static void rx(struct net_device *dev, int bufnum,
 		ofs = 256 - length;
 
 	skb = alloc_skb(length + ARC_HDR_SIZE, GFP_ATOMIC);
-	if (skb == NULL) {
+	if (!skb) {
 		dev->stats.rx_dropped++;
 		return;
 	}

drivers/net/arcnet/rfc1201.c

@@ -178,7 +178,7 @@ static void rx(struct net_device *dev, int bufnum,
 		in->sequence = soft->sequence;
 
 		skb = alloc_skb(length + ARC_HDR_SIZE, GFP_ATOMIC);
-		if (skb == NULL) {
+		if (!skb) {
 			dev->stats.rx_dropped++;
 			return;
 		}
@@ -286,7 +286,7 @@ static void rx(struct net_device *dev, int bufnum,
 			}
 			in->skb = skb = alloc_skb(508 * in->numpackets + ARC_HDR_SIZE,
 						  GFP_ATOMIC);
-			if (skb == NULL) {
+			if (!skb) {
 				arc_printk(D_NORMAL, dev, "(split) memory squeeze, dropping packet.\n");
 				lp->rfc1201.aborted_seq = soft->sequence;
 				dev->stats.rx_dropped++;