mm: compaction: remove unnecessary is_via_compact_memory() checks

Remove from all paths not reachable via /proc/sys/vm/compact_memory.

Link: https://lkml.kernel.org/r/20230519123959.77335-5-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 9f8bfd1..99e4ae4 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -6399,9 +6399,6 @@ static inline bool should_continue_reclaim(struct pglist_data *pgdat,
 		if (!managed_zone(zone))
 			continue;
 
-		if (sc->order == -1) /* is_via_compact_memory() */
-			return false;
-
 		/* Allocation can already succeed, nothing to do */
 		if (zone_watermark_ok(zone, sc->order, min_wmark_pages(zone),
 				      sc->reclaim_idx, 0))
@@ -6598,9 +6595,6 @@ static inline bool compaction_ready(struct zone *zone, struct scan_control *sc)
 {
 	unsigned long watermark;
 
-	if (sc->order == -1) /* is_via_compact_memory() */
-		goto suitable;
-
 	/* Allocation can already succeed, nothing to do */
 	if (zone_watermark_ok(zone, sc->order, min_wmark_pages(zone),
 			      sc->reclaim_idx, 0))
@@ -6610,7 +6604,7 @@ static inline bool compaction_ready(struct zone *zone, struct scan_control *sc)
 	if (compaction_suitable(zone, sc->order,
 				sc->reclaim_idx) == COMPACT_SKIPPED)
 		return false;
-suitable:
+
 	/*
 	 * Compaction is already possible, but it takes time to run and there
 	 * are potentially other callers using the pages just freed. So proceed