drivers/net/tg3.c: change the field used with the TG3_FLAG_10_100_ONLY constant

The constant TG3_FLAG_10_100_ONLY should be used with the tg3_flags field,
not the tg3_flags2 field, as done elsewhere in the same file.
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/tg3.c

@@ -9776,7 +9776,7 @@ static int tg3_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
 			   ADVERTISED_Pause |
 			   ADVERTISED_Asym_Pause;
 
-		if (!(tp->tg3_flags2 & TG3_FLAG_10_100_ONLY))
+		if (!(tp->tg3_flags & TG3_FLAG_10_100_ONLY))
 			mask |= ADVERTISED_1000baseT_Half |
 				ADVERTISED_1000baseT_Full;