e1000: fix mismerge skb_put.

Seems there was a bit of a fix needed to due a bad merge in the legacy
receive path.  Fixes a panic due to skb_over_panic.
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: NAuke Kok <auke-jan.h.kok@intel.com>

drivers/net/e1000/e1000_main.c

@@ -3585,8 +3585,7 @@ e1000_clean_rx_irq(struct e1000_adapter *adapter,
 				buffer_info->skb = skb;
 				goto next_desc;
 			}
-		} else
-			skb_put(skb, length);
+		}
 
 		/* code added for copybreak, this should improve
 		 * performance for small packets with large amounts