ext2: code cleanup for ext2_preread_inode()

Calling bdi_rw_congested() instead of calling
bdi_read_congested() and bdi_write_congested().
Signed-off-by: Chengguang Xu <cgxu519@zoho.com.cn>
Signed-off-by: Jan Kara <jack@suse.cz>

fs/ext2/ialloc.c

@@ -172,9 +172,7 @@ static void ext2_preread_inode(struct inode *inode)
 	struct backing_dev_info *bdi;
 
 	bdi = inode_to_bdi(inode);
-	if (bdi_read_congested(bdi))
-		return;
-	if (bdi_write_congested(bdi))
+	if (bdi_rw_congested(bdi))
 		return;
 
 	block_group = (inode->i_ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb);