net: Remove CONFIG_KMOD from net/ (towards removing CONFIG_KMOD entirely)

Some code here depends on CONFIG_KMOD to not try to load
protocol modules or similar, replace by CONFIG_MODULES
where more than just request_module depends on CONFIG_KMOD
and and also use try_then_request_module in ebtables.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_cong.c b/net/ipv4/tcp_cong.c
index 6a25082..4ec5b4e 100644
--- a/net/ipv4/tcp_cong.c
+++ b/net/ipv4/tcp_cong.c
@@ -115,7 +115,7 @@
 
 	spin_lock(&tcp_cong_list_lock);
 	ca = tcp_ca_find(name);
-#ifdef CONFIG_KMOD
+#ifdef CONFIG_MODULES
 	if (!ca && capable(CAP_SYS_MODULE)) {
 		spin_unlock(&tcp_cong_list_lock);
 
@@ -244,7 +244,7 @@
 	if (ca == icsk->icsk_ca_ops)
 		goto out;
 
-#ifdef CONFIG_KMOD
+#ifdef CONFIG_MODULES
 	/* not found attempt to autoload module */
 	if (!ca && capable(CAP_SYS_MODULE)) {
 		rcu_read_unlock();