sched,bL_switcher: Convert to sched_set_fifo*()

Because SCHED_FIFO is a broken scheduler model (see previous patches)
take away the priority field, the kernel can't possibly make an
informed decision.

In this case, use fifo_low, because it only cares about being above
SCHED_NORMAL. Effectively no change in behaviour.

Cc: rmk+kernel@arm.linux.org.uk
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Nicolas Pitre <nico@fluxnic.net>

arch/arm/common/bL_switcher.c

@@ -270,12 +270,11 @@ static struct bL_thread bL_threads[NR_CPUS];
 static int bL_switcher_thread(void *arg)
 {
 	struct bL_thread *t = arg;
-	struct sched_param param = { .sched_priority = 1 };
 	int cluster;
 	bL_switch_completion_handler completer;
 	void *completer_cookie;
 
-	sched_setscheduler_nocheck(current, SCHED_FIFO, &param);
+	sched_set_fifo_low(current);
 	complete(&t->started);
 
 	do {