bnx2x: fix skb truesize underestimation

bnx2x allocates a full page per fragment.

We must account in skb->truesize, the size of the fragment, not the used
part of it.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -454,7 +454,7 @@ static int bnx2x_fill_frag_skb(struct bnx2x *bp, struct bnx2x_fastpath *fp,
 		skb_fill_page_desc(skb, j, old_rx_pg.page, 0, frag_len);
 
 		skb->data_len += frag_len;
-		skb->truesize += frag_len;
+		skb->truesize += SGE_PAGE_SIZE * PAGES_PER_SGE;
 		skb->len += frag_len;
 
 		frag_size -= frag_len;