coreutils: remove NOSTAT_LEAF_OPTIMIZATION

coreutils is using gnulib as a submodule. In the tarball used by the recipe the
gnulib source is included. The patch comes from
gnulib
https://github.com/coreutils/gnulib/commit/47bf2cf3184027c1eb9c1dfeea5c5b8b2d69710d
In the next release of coreutils this fix will be included.

It caused ‘find’ and ‘du’ to dump core, and it was useful
only for obsolescent Linux filesystems anyway.  Problem reported in:
https://lists.gnu.org/r/bug-gnulib/2020-04/msg00068.html


Quite possibly there is still a serious underlying fts bug with
tight-loop-check and mutating file systems, but if so this patch
should cause the bug to be triggered less often.
* lib/fts.c (enum leaf_optimization): Remove
NOSTAT_LEAF_OPTIMIZATION, as it’s problematic.
(S_MAGIC_REISERFS, S_MAGIC_XFS): Remove; no longer needed.
(leaf_optimization): Remove special cases for ReiserFS and XFS.
(fts_read): Remove NOSTAT_LEAF_OPTIMIZATION code.
* lib/fts_.h (struct _ftsent.fts_n_dirs_remaining):
Remove.  All uses removed.

Signed-off-by: Anders Wallin <anders.wallin@windriver.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>