Grab testr logs even when testr fails.

* devstack-vm-gate-wrap.sh:
Do all testr log processing when we deal with the other logs. Do not
depend on other scripts/functions being called to do this. Downstream
scripts may exit prematurely resulting in a loss of data.

* devstack-vm-gate.sh:
Stop processing testr logs here.

Change-Id: I24144e32f9ba7b279aaec0d3fadcfdf3bc5ef77c