drivers:net: Remove unnecessary OOM messages after netdev_alloc_skb

Emitting netdev_alloc_skb and netdev_alloc_skb_ip_align OOM
messages is unnecessary as there is already a dump_stack
after allocation failures.

Other trivial changes around these removals:

Convert a few comparisons of pointer to 0 to !pointer.
Change flow to remove unnecessary label.
Remove now unused variable.
Hoist assignment from if.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/broadcom/sb1250-mac.c b/drivers/net/ethernet/broadcom/sb1250-mac.c
index e9b35da..e80bfb6 100644
--- a/drivers/net/ethernet/broadcom/sb1250-mac.c
+++ b/drivers/net/ethernet/broadcom/sb1250-mac.c
@@ -831,11 +831,8 @@
 		sb_new = netdev_alloc_skb(dev, ENET_PACKET_SIZE +
 					       SMP_CACHE_BYTES * 2 +
 					       NET_IP_ALIGN);
-		if (sb_new == NULL) {
-			pr_info("%s: sk_buff allocation failed\n",
-			       d->sbdma_eth->sbm_dev->name);
+		if (sb_new == NULL)
 			return -ENOBUFS;
-		}
 
 		sbdma_align_skb(sb_new, SMP_CACHE_BYTES, NET_IP_ALIGN);
 	}