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/tehuti/tehuti.c b/drivers/net/ethernet/tehuti/tehuti.c
index e15cc71..e8824ce 100644
--- a/drivers/net/ethernet/tehuti/tehuti.c
+++ b/drivers/net/ethernet/tehuti/tehuti.c
@@ -1102,10 +1102,9 @@
 	dno = bdx_rxdb_available(db) - 1;
 	while (dno > 0) {
 		skb = netdev_alloc_skb(priv->ndev, f->m.pktsz + NET_IP_ALIGN);
-		if (!skb) {
-			pr_err("NO MEM: netdev_alloc_skb failed\n");
+		if (!skb)
 			break;
-		}
+
 		skb_reserve(skb, NET_IP_ALIGN);
 
 		idx = bdx_rxdb_alloc_elem(db);