t3701: clean up hunk splitting tests

Clean up some test constructs in preparation for extending the tests
in the next commit. There are three small changes, I've grouped them
together as they're so small it didn't seem worth creating three
separate commits.
 1 - "cat file | sed expression" is better written as
     "sed expression file".
 2 - Follow our usual practice of redirecting the output of git
     commands to a file rather than piping it into another command.
 3 - Use test_write_lines rather than 'printf "%s\n"'.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

0 files changed, 0 insertions, 0 deletions