bnx2x: Prevent null pointer dereference on SKB release

On error flows its possible to free an SKB even if it was not allocated.
Signed-off-by: NYuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: NAriel Elior <Ariel.Elior@qlogic.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c

@@ -262,9 +262,9 @@ static u16 bnx2x_free_tx_pkt(struct bnx2x *bp, struct bnx2x_fp_txdata *txdata,
 	if (likely(skb)) {
 		(*pkts_compl)++;
 		(*bytes_compl) += skb->len;
+		dev_kfree_skb_any(skb);
 	}
 
-	dev_kfree_skb_any(skb);
 	tx_buf->first_bd = 0;
 	tx_buf->skb = NULL;