t1005: assert output of ls-files

t1005: assert output of ls-files

Test 'reset should work' in t1005-read-tree-reset.sh compares two files
"expect" and "actual" to assert the expected output of "git ls-files".
Several other tests in the same file also create files "expect" and
"actual", but don't use them in assertions.

Assert output of "git ls-files" in t1005-read-tree-reset.sh to improve
test coverage.

Signed-off-by: Andrei Rybak <rybak.a.v@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>