cxgb4vf: fix bug in Generic Receive Offload

Fix botch in Generic Receive Offload (the Packet Gather List Total length
field wasn't being initialized).

Signed-off-by: Casey Leedom <leedom@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/cxgb4vf/sge.c b/drivers/net/cxgb4vf/sge.c
index f10864d..6a6e18b 100644
--- a/drivers/net/cxgb4vf/sge.c
+++ b/drivers/net/cxgb4vf/sge.c
@@ -1679,6 +1679,7 @@
 				}
 				len = RSPD_LEN(len);
 			}
+			gl.tot_len = len;
 
 			/*
 			 * Gather packet fragments.