[S390] call home support: fix proc handler

8d65af78 "sysctl: remove "struct file *" argument of ->proc_handler"
removed the struct file argument from all proc_handlers but didn't
change the call home proc handler (or call home was merged later).

So fix this now.

Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Hans-Joachim Picht <hans@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

drivers/s390/char/sclp_async.c

@@ -62,7 +62,7 @@ static struct notifier_block call_home_panic_nb = {
 	.priority = INT_MAX,
 };
 
-static int proc_handler_callhome(ctl_table *ctl, int write, struct file *filp,
+static int proc_handler_callhome(struct ctl_table *ctl, int write,
 				 void __user *buffer, size_t *count,
 				 loff_t *ppos)
 {
@@ -100,7 +100,7 @@ static struct ctl_table callhome_table[] = {
 	{
 		.procname	= "callhome",
 		.mode		= 0644,
-		.proc_handler	= &proc_handler_callhome,
+		.proc_handler	= proc_handler_callhome,
 	},
 	{ .ctl_name = 0 }
 };