posix-timers: Clear overrun in common_timer_set()

Keeping the overrun count of the previous setup around is just wrong. The
new setting has nothing to do with the previous one and has to start from a
clean slate.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>

kernel/time/posix-timers.c

@@ -881,6 +881,7 @@ int common_timer_set(struct k_itimer *timr, int flags,
 	timr->it_requeue_pending = (timr->it_requeue_pending + 2) &
 		~REQUEUE_PENDING;
 	timr->it_overrun_last = 0;
+	timr->it_overrun = -1LL;
 
 	/* Switch off the timer when it_value is zero */
 	if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec)