LU-12125 tests: allow racer to specify extra tasks
Add the RACER_EXTRA environment variable to allow racer.sh to run
extra tasks.
Lustre-change: https://review.whamcloud.com/41231
Lustre-commit:
fe2663f18e50023ad5cfe5e07b695378dd27a68e
Test-Parameters: trivial testlist=racer
Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Change-Id: Ic810a248a2dd665a163e0efea8c9af0e4461e09b
Reviewed-on: https://review.whamcloud.com/41961
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>