sysctl: fix unused proc_cap_handler() function warning

Since usermodehelper_table() is marked static now, we get a
warning about it being unused when SYSCTL is disabled:

kernel/umh.c:497:12: error: 'proc_cap_handler' defined but not used [-Werror=unused-function]

Just move it inside of the same #ifdef.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Fixes: 861dc0b ("sysctl: move umh sysctl registration to its own file")
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
[mcgrof: adjust new commit ID for Fixes tag]
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

kernel/umh.c

@@ -494,6 +494,7 @@ int call_usermodehelper(const char *path, char **argv, char **envp, int wait)
 }
 EXPORT_SYMBOL(call_usermodehelper);
 
+#if defined(CONFIG_SYSCTL)
 static int proc_cap_handler(struct ctl_table *table, int write,
 			 void *buffer, size_t *lenp, loff_t *ppos)
 {
@@ -544,7 +545,6 @@ static int proc_cap_handler(struct ctl_table *table, int write,
 	return 0;
 }
 
-#if defined(CONFIG_SYSCTL)
 static struct ctl_table usermodehelper_table[] = {
 	{
 		.procname	= "bset",