watchdog: fix opencoded cpumask_next_wrap() in watchdog_next_cpu()

The dedicated helper is more verbose and efficient comparing to
cpumask_next() followed by cpumask_first().

Signed-off-by: "Yury Norov [NVIDIA]" <[email protected]>
Reviewed-by: Douglas Anderson <[email protected]>

Author: YuryNorov

kernel/watchdog_buddy.c

@@ -12,10 +12,7 @@ static unsigned int watchdog_next_cpu(unsigned int cpu)
 {
 	unsigned int next_cpu;
 
-	next_cpu = cpumask_next(cpu, &watchdog_cpus);
-	if (next_cpu >= nr_cpu_ids)
-		next_cpu = cpumask_first(&watchdog_cpus);
-
+	next_cpu = cpumask_next_wrap(cpu, &watchdog_cpus);
 	if (next_cpu == cpu)
 		return nr_cpu_ids;