[S390] prevent unneccesary loops_per_jiffy recalculation

When the seqfile /proc/cpuinfo gets accesses for each possible cpu
loops_per_jiffy gets recalculated. However its value is only needed
on first access.
In addition loops_per_jiffy should be recalculated when the machine
reports a capability change.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/processor.c b/arch/s390/kernel/processor.c
index 753623b..311e9d7 100644
--- a/arch/s390/kernel/processor.c
+++ b/arch/s390/kernel/processor.c
@@ -46,8 +46,8 @@
 	unsigned long n = (unsigned long) v - 1;
 	int i;
 
-	s390_adjust_jiffies();
 	if (!n) {
+		s390_adjust_jiffies();
 		seq_printf(m, "vendor_id       : IBM/S390\n"
 			   "# processors    : %i\n"
 			   "bogomips per cpu: %lu.%02lu\n",