[Keyman] Adjust path to Jenkinsfile
[Keyman] Adjust path to Jenkinsfile

We only look in `linux` subdirectory.

Change-Id: I5293ad4f19fd42ff2db400b4580207dbb51cd80d

sillsdev/ci-builder-scripts,sillsdev/ci-builder-scripts,sillsdev/ci-builder-scripts