altera_tse: Correct rx packet length

Altera TSE MAC rx DMA transfer starts with the 2 additional bytes for IP
payload alignment. This patch fixes tse_rx() function loop which reads DMA
rx status and extracts packet length from it. Status signalises a whole DMA
transfer length, which is 2 bytes longer than the packet itself.

Signed-off-by: Vlastimil Setka <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/altera/altera_tse_main.c

···
 				   "RCV pktstatus %08X pktlength %08X\n",
 				   pktstatus, pktlength);
 
+		/* DMA trasfer from TSE starts with 2 aditional bytes for
+		 * IP payload alignment. Status returned by get_rx_status()
+		 * contains DMA transfer length. Packet is 2 bytes shorter.
+		 */
+		pktlength -= 2;
+
 		count++;
 		next_entry = (++priv->rx_cons) % priv->rx_ring_size;