preempt/dynamic: Fix setup_preempt_mode() return value

__setup() callbacks expect 1 for success and 0 for failure. Correct the
usage here to reflect that.

Fixes: 826bfeb3 ("preempt/dynamic: Support dynamic preempt with preempt= boot option")
Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrew Halaney <ahalaney@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20211203233203.133581-1-ahalaney@redhat.com

kernel/sched/core.c

@@ -6617,11 +6617,11 @@ static int __init setup_preempt_mode(char *str)
 	int mode = sched_dynamic_mode(str);
 	if (mode < 0) {
 		pr_warn("Dynamic Preempt: unsupported mode: %s\n", str);
-		return 1;
+		return 0;
 	}
 
 	sched_dynamic_update(mode);
-	return 0;
+	return 1;
 }
 __setup("preempt=", setup_preempt_mode);