[PATCH] igb: fix LRO warning

igb supports LRO, but was not setting any hooks to the ->set_flags
ethtool_ops function.  This would trigger warnings if the user tried
to enable or disable LRO.

Based on the patch provided by Stephen Hemminger [off-list ref]

Reported-by: Sergey Kononenko <redacted>
Signed-off-by: Jeff Kirsher <redacted>
CC: Stephen Hemminger <redacted>
---

 drivers/net/igb/igb_ethtool.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/drivers/net/igb/igb_ethtool.c b/drivers/net/igb/igb_ethtool.c
index 3c831f1..44ceb36 100644
--- a/drivers/net/igb/igb_ethtool.c
+++ b/drivers/net/igb/igb_ethtool.c

@@ -2024,6 +2024,10 @@ static struct ethtool_ops igb_ethtool_ops = {
 	.get_ethtool_stats      = igb_get_ethtool_stats,
 	.get_coalesce           = igb_get_coalesce,
 	.set_coalesce           = igb_set_coalesce,
+	.get_flags              = ethtool_op_get_flags,
+#ifdef CONFIG_IGB_LRO
+	.set_flags              = ethtool_op_set_flags,
+#endif
 };
 
 void igb_set_ethtool_ops(struct net_device *netdev)