clocksource: Initialize cs->wd_list

A number of places relies on list_empty(&cs->wd_list), however the
list_head does not get initialized. Do so upon registration, such that
thereafter it is possible to rely on list_empty() correctly reflecting
the list membership status.

Signed-off-by: Peter Zijlstra (Intel) <[e-mail]>
Signed-off-by: Thomas Gleixner <[e-mail]>
Tested-by: Diego Viola <[e-mail]>
Reviewed-by: Rafael J. Wysocki <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Link: https://lkml.kernel.org/r/[e-mail]

kernel/time/clocksource.c

···
 
 static void clocksource_enqueue_watchdog(struct clocksource *cs)
 {
+	INIT_LIST_HEAD(&cs->wd_list);
+
 	if (cs->flags & CLOCK_SOURCE_MUST_VERIFY) {
 		/* cs is a clocksource to be watched. */
 		list_add(&cs->wd_list, &watchdog_list);