Use setResult instead of getExecutor().interrupt to set FAILURE

Use setResult instead of getExecutor().interrupt to set FAILURE

getExecutor().interrupt(FAILURE) flag the build as aborted event if the final status is FAILURE.
This influence triggers such as email.

07:28:26 lttng-modules_VERSION_param-build #334163 (v4.12.14) completed with status SUCCESS
07:28:26 lttng-modules_VERSION_param-build #334160 (v4.15-rc3) completed with status FAILURE
...
07:28:26 lttng-modules_VERSION_param-build #334220 (v2.6.37.6) completed with status SUCCESS
07:28:26 Build was aborted

Marked as "aborted".

07:28:26 Started calculate disk usage of build
07:28:26 Finished Calculation of disk usage of build in 0 seconds
07:28:26 Started calculate disk usage of workspace
07:28:26 Finished Calculation of disk usage of workspace in 0 seconds
07:28:26 [WS-CLEANUP] Deleting project workspace...[WS-CLEANUP] done
07:28:26 No emails were triggered.

An email should have been fired here.

07:28:26 Finished: FAILURE

Final status is Failure. But no email were sent.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>