[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>
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index fa8af4e..07cffe2 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -127,15 +127,14 @@
 	cputime64_t busy_time;
 
 	cur_wall_time = jiffies64_to_cputime64(get_jiffies_64());
-	busy_time = cputime64_add(kstat_cpu(cpu).cpustat.user,
-			kstat_cpu(cpu).cpustat.system);
+	busy_time  = kstat_cpu(cpu).cpustat.user;
+	busy_time += kstat_cpu(cpu).cpustat.system;
+	busy_time += kstat_cpu(cpu).cpustat.irq;
+	busy_time += kstat_cpu(cpu).cpustat.softirq;
+	busy_time += kstat_cpu(cpu).cpustat.steal;
+	busy_time += kstat_cpu(cpu).cpustat.nice;
 
-	busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.irq);
-	busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.softirq);
-	busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.steal);
-	busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.nice);
-
-	idle_time = cputime64_sub(cur_wall_time, busy_time);
+	idle_time = cur_wall_time - busy_time;
 	if (wall)
 		*wall = (cputime64_t)jiffies_to_usecs(cur_wall_time);
 
@@ -442,24 +441,24 @@
 		cur_idle_time = get_cpu_idle_time(j, &cur_wall_time);
 		cur_iowait_time = get_cpu_iowait_time(j, &cur_wall_time);
 
-		wall_time = (unsigned int) cputime64_sub(cur_wall_time,
-				j_dbs_info->prev_cpu_wall);
+		wall_time = (unsigned int)
+			(cur_wall_time - j_dbs_info->prev_cpu_wall);
 		j_dbs_info->prev_cpu_wall = cur_wall_time;
 
-		idle_time = (unsigned int) cputime64_sub(cur_idle_time,
-				j_dbs_info->prev_cpu_idle);
+		idle_time = (unsigned int)
+			(cur_idle_time - j_dbs_info->prev_cpu_idle);
 		j_dbs_info->prev_cpu_idle = cur_idle_time;
 
-		iowait_time = (unsigned int) cputime64_sub(cur_iowait_time,
-				j_dbs_info->prev_cpu_iowait);
+		iowait_time = (unsigned int)
+			(cur_iowait_time - j_dbs_info->prev_cpu_iowait);
 		j_dbs_info->prev_cpu_iowait = cur_iowait_time;
 
 		if (dbs_tuners_ins.ignore_nice) {
 			cputime64_t cur_nice;
 			unsigned long cur_nice_jiffies;
 
-			cur_nice = cputime64_sub(kstat_cpu(j).cpustat.nice,
-					 j_dbs_info->prev_cpu_nice);
+			cur_nice = kstat_cpu(j).cpustat.nice -
+					j_dbs_info->prev_cpu_nice;
 			/*
 			 * Assumption: nice time between sampling periods will
 			 * be less than 2^32 jiffies for 32 bit sys