jjb/common: fix guppy test templates

jjb/common: fix guppy test templates

A previous change[1] moved to rely on test templates for test plans,
instead of passing --test when using releng-scripts, however when this
script was added for guppy[2], it was copied from an older version.

Fix this version to not use --test either.

[1] 142b04edc103 jjb/common: run-tests: rely on templates for test plans
[2] b76de43474cf (gerrit/master) Add release job for guppy

Change-Id: I98e00695ddb49a917cda40743b8c7328987ffe98
Signed-off-by: Kevin Hilman <khilman@baylibre.com>