Merge branch 'ps/reftable-unit-test-nfs-workaround'

A unit test for reftable code tried to enumerate all files in a
directory after reftable operations and expected to see nothing but
the files it wanted to leave there, but was fooled by .nfs* cruft
files left, which has been corrected.

* ps/reftable-unit-test-nfs-workaround:
  reftable: fix tests being broken by NFS' delete-after-close semantics

diff --cc reftable/stack_test.c
Simple merge