properly __init-annotate pm_sysrq_init()

This is used only as argument to subsys_initcall().
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

kernel/power/poweroff.c

@@ -37,7 +37,7 @@ static struct sysrq_key_op	sysrq_poweroff_op = {
 	.enable_mask	= SYSRQ_ENABLE_BOOT,
 };
 
-static int pm_sysrq_init(void)
+static int __init pm_sysrq_init(void)
 {
 	register_sysrq_key('o', &sysrq_poweroff_op);
 	return 0;