[NETDRV]: Perform missing csum_offset conversions

When csum_offset was introduced we did a conversion from csum to
csum_offset where applicable.  A couple of drivers were missed in
this process.

It was harmless to begin with since the two fields coincided.  Now
that we've made them different with the addition of csum_start, the
missed drivers must be converted or they can't send packets out at
all that require checksum offload.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/e1000/e1000_main.c b/drivers/net/e1000/e1000_main.c
index 610216e..48e2ade 100644
--- a/drivers/net/e1000/e1000_main.c
+++ b/drivers/net/e1000/e1000_main.c
@@ -2959,7 +2959,8 @@
 
 		context_desc->lower_setup.ip_config = 0;
 		context_desc->upper_setup.tcp_fields.tucss = css;
-		context_desc->upper_setup.tcp_fields.tucso = css + skb->csum;
+		context_desc->upper_setup.tcp_fields.tucso =
+			css + skb->csum_offset;
 		context_desc->upper_setup.tcp_fields.tucse = 0;
 		context_desc->tcp_seg_setup.data = 0;
 		context_desc->cmd_and_length = cpu_to_le32(E1000_TXD_CMD_DEXT);