posix-cpu-timers: Remove confusing return value override

The end of the function cannot be reached with an error in variable
ret. Unconfuse reviewers about that.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210726125513.271824-5-frederic@kernel.org

kernel/time/posix-cpu-timers.c

@@ -744,8 +744,6 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
 		 */
 		cpu_timer_fire(timer);
 	}
-
-	ret = 0;
  out:
 	rcu_read_unlock();
 	if (old)