net/af_iucv: clean up a try_then_request_module()

Use IS_ENABLED(CONFIG_IUCV) to determine whether the iucv_if symbol
is available, and let depmod deal with the module dependency.

This was introduced back with commit 6fcd61f7 ("af_iucv: use
loadable iucv interface"). And to avoid sprinkling IS_ENABLED() over
all the code, we're keeping the indirection through pr_iucv->...().
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/iucv/af_iucv.c

@@ -2278,7 +2278,7 @@ static int __init afiucv_init(void)
 {
 	int err;
 
-	if (MACHINE_IS_VM) {
+	if (MACHINE_IS_VM && IS_ENABLED(CONFIG_IUCV)) {
 		cpcmd("QUERY USERID", iucv_userid, sizeof(iucv_userid), &err);
 		if (unlikely(err)) {
 			WARN_ON(err);
@@ -2286,11 +2286,7 @@ static int __init afiucv_init(void)
 			goto out;
 		}
 
-		pr_iucv = try_then_request_module(symbol_get(iucv_if), "iucv");
-		if (!pr_iucv) {
-			printk(KERN_WARNING "iucv_if lookup failed\n");
-			memset(&iucv_userid, 0, sizeof(iucv_userid));
-		}
+		pr_iucv = &iucv_if;
 	} else {
 		memset(&iucv_userid, 0, sizeof(iucv_userid));
 		pr_iucv = NULL;
@@ -2324,17 +2320,13 @@ static int __init afiucv_init(void)
 out_proto:
 	proto_unregister(&iucv_proto);
 out:
-	if (pr_iucv)
-		symbol_put(iucv_if);
 	return err;
 }
 
 static void __exit afiucv_exit(void)
 {
-	if (pr_iucv) {
+	if (pr_iucv)
 		afiucv_iucv_exit();
-		symbol_put(iucv_if);
-	}
 
 	unregister_netdevice_notifier(&afiucv_netdev_notifier);
 	dev_remove_pack(&iucv_packet_type);