[NET] ethtool: fix oops by testing correct struct member

Noticed by Willy Tarreau.

Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index 27ce168..2797e28 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -437,7 +437,7 @@
 {
 	struct ethtool_pauseparam pauseparam;
 
-	if (!dev->ethtool_ops->get_pauseparam)
+	if (!dev->ethtool_ops->set_pauseparam)
 		return -EOPNOTSUPP;
 
 	if (copy_from_user(&pauseparam, useraddr, sizeof(pauseparam)))