e1000e: Simple optimizations in e1000_xmit_frame

After an e1000 patch from Krishna Kumar <krkumar2@in.ibm.com>.

Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/net/e1000e/netdev.c b/drivers/net/e1000e/netdev.c
index 3a0bb2a..600538b 100644
--- a/drivers/net/e1000e/netdev.c
+++ b/drivers/net/e1000e/netdev.c
@@ -3424,14 +3424,13 @@
 	unsigned int max_per_txd = E1000_MAX_PER_TXD;
 	unsigned int max_txd_pwr = E1000_MAX_TXD_PWR;
 	unsigned int tx_flags = 0;
-	unsigned int len = skb->len;
+	unsigned int len = skb->len - skb->data_len;
 	unsigned long irq_flags;
-	unsigned int nr_frags = 0;
-	unsigned int mss = 0;
+	unsigned int nr_frags;
+	unsigned int mss;
 	int count = 0;
 	int tso;
 	unsigned int f;
-	len -= skb->data_len;
 
 	if (test_bit(__E1000_DOWN, &adapter->state)) {
 		dev_kfree_skb_any(skb);
@@ -3459,7 +3458,7 @@
 		* points to just header, pull a few bytes of payload from
 		* frags into skb->data */
 		hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb);
-		if (skb->data_len && (hdr_len == (skb->len - skb->data_len))) {
+		if (skb->data_len && (hdr_len == len)) {
 			unsigned int pull_size;
 
 			pull_size = min((unsigned int)4, skb->data_len);