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/socket.c b/net/socket.c
index 3e8d4e3..2b7a4b5 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -1142,7 +1142,7 @@
 
 	sock->type = type;
 
-#if defined(CONFIG_KMOD)
+#ifdef CONFIG_MODULES
 	/* Attempt to load a protocol module if the find failed.
 	 *
 	 * 12/09/1996 Marcin: But! this makes REALLY only sense, if the user