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>

drivers/net/ethernet/atheros/atlx/atl2.c

@@ -437,9 +437,6 @@ static void atl2_intr_rx(struct atl2_adapter *adapter)
 			/* alloc new buffer */
 			skb = netdev_alloc_skb_ip_align(netdev, rx_size);
 			if (NULL == skb) {
-				printk(KERN_WARNING
-					"%s: Mem squeeze, deferring packet.\n",
-					netdev->name);
 				/*
 				 * Check that some rx space is free. If not,
 				 * free one and mark stats->rx_dropped++.