Changes

jobs/gerrit: osmo-ttcn3-hacks: tweak make lines

* The "make clean" is not needed, as the osmo-ttcn3-hacks.git repository
  is a fresh clone of code that was submitted to gerrit.
* The "make deps" is not needed, as "make compile" depends on the deps
  target.
* Combine the cd and make lines.
* Remove ; at the end of lines, as it is not needed
* Switch " and ', so variables can be used with less escaping in future
  patches in this block.

Change-Id: Iac179bfb26478ecab51f47e469b4be7b0f9a5a94