ipvs: Create init functions for estimator code

Commit 8ab19ea36c5c5340ff598e4d15fc084eb65671dc ("ipvs: Fix possible deadlock
in estimator code") fixed a deadlock condition, but that condition can only
happen during unload of IPVS, because during normal operation there is at least
our global stats structure in the estimator list. The mod_timer() and
del_timer_sync() calls are actually initialization and cleanup code in
disguise. Let's make it explicit and move them to their own init and cleanup
function.

Signed-off-by: Sven Wegener <sven.wegener@stealer.net>
Signed-off-by: Simon Horman <horms@verge.net.au>

diff --git a/net/ipv4/ipvs/ip_vs_est.c b/net/ipv4/ipvs/ip_vs_est.c
index 5a20f93..4fb620e 100644
--- a/net/ipv4/ipvs/ip_vs_est.c
+++ b/net/ipv4/ipvs/ip_vs_est.c
@@ -124,8 +124,6 @@
 	est->outbps = stats->outbps<<5;
 
 	spin_lock_bh(&est_lock);
-	if (list_empty(&est_list))
-		mod_timer(&est_timer, jiffies + 2 * HZ);
 	list_add(&est->list, &est_list);
 	spin_unlock_bh(&est_lock);
 }
@@ -136,11 +134,6 @@
 
 	spin_lock_bh(&est_lock);
 	list_del(&est->list);
-	while (list_empty(&est_list) && try_to_del_timer_sync(&est_timer) < 0) {
-		spin_unlock_bh(&est_lock);
-		cpu_relax();
-		spin_lock_bh(&est_lock);
-	}
 	spin_unlock_bh(&est_lock);
 }
 
@@ -160,3 +153,14 @@
 	est->inbps = 0;
 	est->outbps = 0;
 }
+
+int __init ip_vs_estimator_init(void)
+{
+	mod_timer(&est_timer, jiffies + 2 * HZ);
+	return 0;
+}
+
+void ip_vs_estimator_cleanup(void)
+{
+	del_timer_sync(&est_timer);
+}