[PATCH v3] drivers/base/memory: simplify outputting of valid_zones_show()

[Shiyang Ruan <ruansy.fnst@fujitsu.com>]

No need to specific position at the first writing to the buf because the
@len is always 0 at this time.  Use sysfs_emit() instead to simplify it.
Also avoid setting/checking default_zone with a conditional operator.

Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Acked-by: David Hildenbrand <david@redhat.com>
---
 drivers/base/memory.c | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 67858eeb92ed..92e6bc6eb21e 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -455,7 +455,7 @@ static ssize_t valid_zones_show(struct device *dev,
 	struct memory_group *group = mem->group;
 	struct zone *default_zone;
 	int nid = mem->nid;
-	int len = 0;
+	int len;
 
 	/*
 	 * Check the existing zone. Make sure that we do that only on the
@@ -466,22 +466,18 @@ static ssize_t valid_zones_show(struct device *dev,
 		 * If !mem->zone, the memory block spans multiple zones and
 		 * cannot get offlined.
 		 */
-		default_zone = mem->zone;
-		if (!default_zone)
-			return sysfs_emit(buf, "%s\n", "none");
-		len += sysfs_emit_at(buf, len, "%s", default_zone->name);
-		goto out;
+		return sysfs_emit(buf, "%s\n",
+				  mem->zone ? mem->zone->name : "none");
 	}
 
 	default_zone = zone_for_pfn_range(MMOP_ONLINE, nid, group,
 					  start_pfn, nr_pages);
 
-	len += sysfs_emit_at(buf, len, "%s", default_zone->name);
+	len = sysfs_emit(buf, "%s", default_zone->name);
 	len += print_allowed_zone(buf, len, nid, group, start_pfn, nr_pages,
 				  MMOP_ONLINE_KERNEL, default_zone);
 	len += print_allowed_zone(buf, len, nid, group, start_pfn, nr_pages,
 				  MMOP_ONLINE_MOVABLE, default_zone);
-out:
 	len += sysfs_emit_at(buf, len, "\n");
 	return len;
 }
-- 
2.43.0