tests: use 'test_must_be_empty' instead of 'test_cmp <empty> <out>'

[git] / t / t4100 / t-apply-6.expect

 Makefile         |    2 +-
 git-fetch-script |   41 +++++++++++++++++++++++++++++++++++++++++
 git-pull-script  |   34 +---------------------------------
 3 files changed, 43 insertions(+), 34 deletions(-)
 create git-fetch-script