jobs: preserve suffix while building in mock

Preserve the suffix used while building the src.rpm also when building rpms in
mock. Also creates a vault directory on $WORKSPACE/tmp for all the jobs that
get removed and created at the start of the job

Change-Id: Ie5e4cd292a2c9c8b641ca57e31b80f5a05b81e68
Signed-off-by: Sandro Bonazzola <sbonazzo@redhat.com>