nilfs2: use list_first_entry

This uses list_first_entry macro instead of list_entry if it's used to
get the first entry.
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

fs/nilfs2/recovery.c

@@ -387,9 +387,9 @@ static int nilfs_scan_dsync_log(struct the_nilfs *nilfs, sector_t start_blocknr,
 static void dispose_recovery_list(struct list_head *head)
 {
 	while (!list_empty(head)) {
-		struct nilfs_recovery_block *rb
-			= list_entry(head->next,
-				     struct nilfs_recovery_block, list);
+		struct nilfs_recovery_block *rb;
+
+		rb = list_first_entry(head, struct nilfs_recovery_block, list);
 		list_del(&rb->list);
 		kfree(rb);
 	}
@@ -416,9 +416,9 @@ static int nilfs_segment_list_add(struct list_head *head, __u64 segnum)
 void nilfs_dispose_segment_list(struct list_head *head)
 {
 	while (!list_empty(head)) {
-		struct nilfs_segment_entry *ent
-			= list_entry(head->next,
-				     struct nilfs_segment_entry, list);
+		struct nilfs_segment_entry *ent;
+
+		ent = list_first_entry(head, struct nilfs_segment_entry, list);
 		list_del(&ent->list);
 		kfree(ent);
 	}

fs/nilfs2/segment.c

@@ -957,8 +957,8 @@ static int nilfs_segctor_apply_buffers(struct nilfs_sc_info *sci,
 
  dispose_buffers:
 	while (!list_empty(listp)) {
-		bh = list_entry(listp->next, struct buffer_head,
-				b_assoc_buffers);
+		bh = list_first_entry(listp, struct buffer_head,
+				      b_assoc_buffers);
 		list_del_init(&bh->b_assoc_buffers);
 		brelse(bh);
 	}