Merge branch 'nd/clone-case-smashing-warning'

Recently added check for case smashing filesystems did not
correctly utilize the cached stat information, leading to false
breakage detected by our test suite, which has been corrected.

* nd/clone-case-smashing-warning:
  clone: fix colliding file detection on APFS

diff --cc entry.c
Simple merge

diff --cc t/t5601-clone.sh
Simple merge