gplugin/gplugin

make sure g_assert_no_error is checked before return values.

Testing Done:
Compiled and ran the unit tests locally.

Reviewed at https://reviews.imfreedom.org/r/327/
REVIEWBOARD_URL = "https://reviews.imfreedom.org/"
REPOSITORY = "gplugin/gplugin"
REPOSITORY_TYPE = "mercurial"
BRANCH = "default"
LAND_DEST_BRANCH = "default"
LAND_PUSH = False