t1404: don't create unused file

Some tests in file t1404-update-ref-errors.sh create file "unchanged" as the expected side for a test_cmp assertion at the end of the test for output of "git for-each-ref". Test 'no bogus intermediate values during delete' also creates a file named "unchanged" using "git for-each-ref". However, the file isn't used for any assertions in the test. Instead, "git rev-parse" is used to compare the reference with variable $D. Don't create unused file "unchanged" in test 'no bogus intermediate values during delete' of t1404-update-ref-errors.sh. Signed-off-by: Andrei Rybak <rybak.a.v@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>