build: update gnulib for syntax-check improvement

Commit 5b3e538 proved useful enough to migrate to gnulib after
enhancing it to be more generic, which in turn pointed out that
commit a2c811db missed an offender.

* gnulib: Update to latest.
* cfg.mk (sc_prohibit_reversed_compare_failure): Delete, now that
gnulib provides it.
* tests/ls/dangle: Fix last offender.

1 files changed, 0 insertions, 0 deletions

diff --git a/gnulib b/gnulib
-Subproject 908690cb743e69c73b42ae310807b29800c8764
+Subproject a5f6df2b1f3f0fdc73635de3ad285d21703dab1