[S390] cputime: add sparse checking and cleanup

Make cputime_t and cputime64_t nocast to enable sparse checking to
detect incorrect use of cputime. Drop the cputime macros for simple
scalar operations. The conversion macros are still needed.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

drivers/macintosh/rack-meter.c

@@ -83,11 +83,10 @@ static inline cputime64_t get_cpu_idle_time(unsigned int cpu)
 {
 	cputime64_t retval;
 
-	retval = cputime64_add(kstat_cpu(cpu).cpustat.idle,
-			kstat_cpu(cpu).cpustat.iowait);
+	retval = kstat_cpu(cpu).cpustat.idle + kstat_cpu(cpu).cpustat.iowait;
 
 	if (rackmeter_ignore_nice)
-		retval = cputime64_add(retval, kstat_cpu(cpu).cpustat.nice);
+		retval += kstat_cpu(cpu).cpustat.nice;
 
 	return retval;
 }
@@ -220,13 +219,11 @@ static void rackmeter_do_timer(struct work_struct *work)
 	int i, offset, load, cumm, pause;
 
 	cur_jiffies = jiffies64_to_cputime64(get_jiffies_64());
-	total_ticks = (unsigned int)cputime64_sub(cur_jiffies,
-						  rcpu->prev_wall);
+	total_ticks = (unsigned int) (cur_jiffies - rcpu->prev_wall);
 	rcpu->prev_wall = cur_jiffies;
 
 	total_idle_ticks = get_cpu_idle_time(cpu);
-	idle_ticks = (unsigned int) cputime64_sub(total_idle_ticks,
-				rcpu->prev_idle);
+	idle_ticks = (unsigned int) (total_idle_ticks - rcpu->prev_idle);
 	rcpu->prev_idle = total_idle_ticks;
 
 	/* We do a very dumb calculation to update the LEDs for now,