on_each_cpu(): kill unused 'retry' parameter

It's not even passed on to smp_call_function() anymore, since that
was removed. So kill it.

Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 73401e8..f1a38a6 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -322,7 +322,7 @@
 {
 	if (!cpu_has_feature(CPU_FTR_PURR))
 		return;
-	on_each_cpu(snapshot_tb_and_purr, NULL, 0, 1);
+	on_each_cpu(snapshot_tb_and_purr, NULL, 1);
 }
 
 /*