s390/cputime: simplify account_system_index_scaled

The account_system_index_scaled gets two cputime values, a raw value
derived from CPU timer deltas and a scaled value. The scaled value
is always calculated from the raw value, the code can be simplified
by moving the scale_vtime call into account_system_index_scaled.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/kernel/vtime.c

@@ -110,11 +110,10 @@ static inline u64 scale_vtime(u64 vtime)
 	return vtime;
 }
 
-static void account_system_index_scaled(struct task_struct *p,
-					u64 cputime, u64 scaled,
+static void account_system_index_scaled(struct task_struct *p, u64 cputime,
 					enum cpu_usage_stat index)
 {
-	p->stimescaled += cputime_to_nsecs(scaled);
+	p->stimescaled += cputime_to_nsecs(scale_vtime(cputime));
 	account_system_index_time(p, cputime_to_nsecs(cputime), index);
 }
 
@@ -176,14 +175,11 @@ static int do_account_vtime(struct task_struct *tsk)
 	}
 
 	if (system)
-		account_system_index_scaled(tsk, system, scale_vtime(system),
-					    CPUTIME_SYSTEM);
+		account_system_index_scaled(tsk, system, CPUTIME_SYSTEM);
 	if (hardirq)
-		account_system_index_scaled(tsk, hardirq, scale_vtime(hardirq),
-					    CPUTIME_IRQ);
+		account_system_index_scaled(tsk, hardirq, CPUTIME_IRQ);
 	if (softirq)
-		account_system_index_scaled(tsk, softirq, scale_vtime(softirq),
-					    CPUTIME_SOFTIRQ);
+		account_system_index_scaled(tsk, softirq, CPUTIME_SOFTIRQ);
 
 	steal = S390_lowcore.steal_timer;
 	if ((s64) steal > 0) {