patchbomb: fix 'echo -en' bashism in test-patchbomb
The echo command doesn't accept options in some shells.
printf is required by the SUSv2 (Single UNIX Specification v2).
#!/bin/sh
hg init test
cd test
echo foo > a
hg ci -Ama
hg up -r0000
echo bar > a
echo % should issue warning
hg ci -Amb
hg up -r0000
echo stuffy > a
echo % should not issue warning
hg ci -q -Amc
hg up -r0000
echo crap > a
hg branch testing
echo % should not issue warning
hg ci -q -Amd