Fix run-build succeeding always

Make sure the exit code of run-build is passed, so that failed jobs
are listed failed in jenkins.

This is done be removing the redirect completely, and relying on the
jenkins console log. This commit will change log summary link is changed
from artifacts:

https://ci.trustedfirmware.org/job/tf-m-build-config/34823/artifact/build.log/*view*/

to jenkins console text:

https://ci.trustedfirmware.org/job/tf-m-build-config/34823/consoleText

Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Change-Id: I038ce8b15d7dbc47ecd43467e08a9b6f0b1f72ab
2 files changed