PM / devfreq: passive: Return non-error when not-supported event is required

Each devfreq governor specifies the supported governor event
such as GOV_START and GOV_STOP. When not-supported event is required,
just return non-error. But, commit ce9a0d88d97a ("PM / devfreq: Add
cpu based scaling support to passive governor") returned the error
value. So that return non-error value when not-supported event is required.

Fixes: ce9a0d88d97a ("PM / devfreq: Add cpu based scaling support to passive governor")
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Author: chanwoochoi

drivers/devfreq/governor_passive.c

@@ -402,7 +402,7 @@ static int devfreq_passive_event_handler(struct devfreq *devfreq,
 {
 	struct devfreq_passive_data *p_data
 			= (struct devfreq_passive_data *)devfreq->data;
-	int ret = -EINVAL;
+	int ret = 0;
 
 	if (!p_data)
 		return -EINVAL;