tests: test/mon/osd-erasure-code-profile.sh uses ceph-helpers.sh

tests: test/mon/osd-erasure-code-profile.sh uses ceph-helpers.sh

Instead of using mon-test-helpers.sh, primarily because the kill_daemon
function implemented in mon-test-helpers.sh is not as good as
ceph-helpers.sh.

Instead of having tests that share the same monitor, each test now runs
on a fresh monitor. The test writer no longer has to worry that it will
be re-using the pool or profile from a previous test. That causes
problems that are difficult to diagnose and the overhead of running a
new monitor is not so high.

Signed-off-by: Loic Dachary <ldachary@redhat.com>