posix: fix one-time timer for SIGEV_SIGNAL

For SIGEV_SIGNAL, the function zephyr_timer_wrapper() is the handler
between kernel and posix layer.
Here, for one-time timer, reload is equal to 0 and function returns.
As a consequence, handler function was never called.

Signed-off-by: Noemie Gillet <[email protected]>

Author: Noemie Gillet

lib/posix/options/timer.c

@@ -43,7 +43,6 @@ static void zephyr_timer_wrapper(struct k_timer *ztimer)
 	if (timer->reload == 0U) {
 		timer->status = NOT_ACTIVE;
 		LOG_DBG("timer %p not active", timer);
-		return;
 	}
 
 	if (timer->evp.sigev_notify == SIGEV_NONE) {