test_job_process.c: Ignore Sandbox variables when printing environment variables

When running in the gentoo emerge sandbox, some environment variables
like SANDBOX_ACTIVE, LD_PRELOAD are added.
It confuses the unit tests that check precisely for the variables added
by upstart.
Remove the variables added by sandboxing when testing variables (child
called with argument TEST_ENVIRONMENT).

BUG=b:232122437
TEST=FEATURES=test emerge-eve upstart, check test_job_process passes.

Change-Id: Ifadc2cbcd00ad22039377ffd1fad8a59ba10a7fa
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/upstart/+/3709118
Reviewed-by: Allen Webb <allenwebb@google.com>
Commit-Queue: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Fergus Dall <sidereal@google.com>
Tested-by: Gwendal Grignou <gwendal@chromium.org>
1 file changed