ipv4: Do cleanup for ip_mr_init

Same as ip6_mr_init(), make ip_mr_init() return errno if fails.
But do not do error handling in inet_init(), just print a msg.

Signed-off-by: Wang Chen <wangchen@cn.fujitsu.com>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 300ab0c..438fab9 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -1878,16 +1878,36 @@
  *	Setup for IP multicast routing
  */
 
-void __init ip_mr_init(void)
+int __init ip_mr_init(void)
 {
+	int err;
+
 	mrt_cachep = kmem_cache_create("ip_mrt_cache",
 				       sizeof(struct mfc_cache),
 				       0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
 				       NULL);
+	if (!mrt_cachep)
+		return -ENOMEM;
+
 	setup_timer(&ipmr_expire_timer, ipmr_expire_process, 0);
-	register_netdevice_notifier(&ip_mr_notifier);
+	err = register_netdevice_notifier(&ip_mr_notifier);
+	if (err)
+		goto reg_notif_fail;
 #ifdef CONFIG_PROC_FS
-	proc_net_fops_create(&init_net, "ip_mr_vif", 0, &ipmr_vif_fops);
-	proc_net_fops_create(&init_net, "ip_mr_cache", 0, &ipmr_mfc_fops);
+	err = -ENOMEM;
+	if (!proc_net_fops_create(&init_net, "ip_mr_vif", 0, &ipmr_vif_fops))
+		goto proc_vif_fail;
+	if (!proc_net_fops_create(&init_net, "ip_mr_cache", 0, &ipmr_mfc_fops))
+		goto proc_cache_fail;
 #endif
+	return 0;
+reg_notif_fail:
+	kmem_cache_destroy(mrt_cachep);
+#ifdef CONFIG_PROC_FS
+proc_vif_fail:
+	unregister_netdevice_notifier(&ip_mr_notifier);
+proc_cache_fail:
+	proc_net_remove(&init_net, "ip_mr_vif");
+#endif
+	return err;
 }