jjb/common: fix DIST_BUILD_TOPIC usage
Fix use of DIST_BUILD_TOPIC to be used with --build-version (instead
of --name). build-version is the key used in the backend to collect
all related jobs, whereas --name is just for the LAVA job name.
The email report request also uses $DIST_BUILD_TOPIC, which will allow
and email report to be generated with results for all tests with the
same $DIST_BUILD_TOPIC.
Bug-AGL: SPEC-2646
Change-Id: I8657270bcbbc06f361b079a07f3922cf4e782e1a
Signed-off-by: Kevin Hilman <khilman@baylibre.com>