f2fs: fix error path in init_inode_metadata

If we fail in this path:
->init_inode_metadata
  ->make_empty_dir
    ->get_new_data_page
      ->grab_cache_page return -ENOMEM

We will bug on in error path of init_inode_metadata when call remove_inode_page
because i_block = 2 (one inode block will be released later & one dentry block).

We should release the dentry block in init_inode_metadata to avoid this BUG_ON,
and avoid leak of dentry block resource, because we never have second chance to
release that block in ->evict_inode as in upper error path we make this inode
'bad'.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/dir.c

@@ -376,11 +376,11 @@ static struct page *init_inode_metadata(struct inode *inode,
 
 put_error:
 	f2fs_put_page(page, 1);
+error:
 	/* once the failed inode becomes a bad inode, i_mode is S_IFREG */
 	truncate_inode_pages(&inode->i_data, 0);
 	truncate_blocks(inode, 0);
 	remove_dirty_dir_inode(inode);
-error:
 	remove_inode_page(inode);
 	return ERR_PTR(err);
 }