sched: Constify function scope static struct sched_param usage

Function-scope statics are discouraged because they are
easily overlooked and can cause subtle bugs/races due to
their global (non-SMP safe) nature.

Linus noticed that we did this for sched_param - at minimum
make the const.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: Message-ID: <AANLkTinotRxScOHEb0HgFgSpGPkq_6jKTv5CfvnQM=ee@mail.gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/kthread.c b/kernel/kthread.c
index 5355cfd..c55afba9 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -148,7 +148,7 @@
 	wait_for_completion(&create.done);
 
 	if (!IS_ERR(create.result)) {
-		static struct sched_param param = { .sched_priority = 0 };
+		static const struct sched_param param = { .sched_priority = 0 };
 		va_list args;
 
 		va_start(args, namefmt);