tests: replace `echo -n` with `printf` per check-code
Differential Revision: https://phab.mercurial-scm.org/D3749
--- a/tests/test-commit-interactive-curses.t Thu Jun 14 14:04:26 2018 -0700
+++ b/tests/test-commit-interactive-curses.t Fri Jun 15 10:14:32 2018 -0400
@@ -215,7 +215,7 @@
+hello world
Make file empty
- $ echo -n > x
+ $ printf "" > x
$ cat <<EOF >testModeCommands
> X
> EOF