[autotest] Fix logging for minidump symbolication failures

I had bad parens.  Also, I wasn't returning an error code when we
decided to not talk to the dev server, so we weren't printing
errors in that case.

BUG=chromium-os:30447
TEST=move /usr/bin/minidump_stackwalk out of the way, and run_remote_tests a test that crashes.
TEST=there should be WARNINGs about the inability to symbolicate the crash dump; no exceptions.

Change-Id: Icea86f72203cc6d363437203abbf43949554a767
Reviewed-on: https://gerrit.chromium.org/gerrit/21778
Tested-by: Chris Masone <cmasone@chromium.org>
Reviewed-by: Scott Zawalski <scottz@chromium.org>
Commit-Ready: Chris Masone <cmasone@chromium.org>
1 file changed