sched: Introduce task_is_running()

Replace a bunch of 'p->state == TASK_RUNNING' with a new helper:
task_is_running(p).

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210611082838.222401495@infradead.org
diff --git a/mm/compaction.c b/mm/compaction.c
index 84fde27..725f564 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1955,7 +1955,7 @@ static inline bool is_via_compact_memory(int order)
 
 static bool kswapd_is_running(pg_data_t *pgdat)
 {
-	return pgdat->kswapd && (pgdat->kswapd->state == TASK_RUNNING);
+	return pgdat->kswapd && task_is_running(pgdat->kswapd);
 }
 
 /*