Merge branch 'es/test-cmp-typocatcher'

A test helper "test_cmp A B" was taught to diagnose missing files A
or B as a bug in test, but some tests legitimately wanted to notice
a failure to even create file B as an error, in addition to leaving
the expected result in it, and were misdiagnosed as a bug.  This
has been corrected.

* es/test-cmp-typocatcher:
  Revert "test_cmp: diagnose incorrect arguments"

diff --cc t/test-lib-functions.sh
Simple merge