Commit ba38c27e ("f2fs: enhance lookup xattr") introduces
lookup_all_xattrs duplicating from read_all_xattrs, which leaves
lots of similar codes in between them, so introduce new help
read_xattr_block to clean up redundant codes.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>