Silence dpkg-query errors in install-build-deps.

Silence dpkg-query errors in install-build-deps.

On leading-edge Ubuntu versions there are no LTS backport packages, and
dpkg-query prints an error about nothing matching the wildcard to
stderr, which has caused at least one user to think the script didn't
install mesa correctly. The script handles this case just fine, though
(it expands to an empty array and sets mesa_variant to emptystring,
whcih is correct), so just redirect stderr to avoid this spurious error
message.

BUG=

Committed: https://crrev.com/12cd9f6cf09631a18f11f123cc02e753dfcaa199
Cr-Commit-Position: refs/heads/master@{#377332}

[Torne, 2016-02-23 10:51:06]

torne@chromium.org changed reviewers:
+ dpranke@chromium.org

[Dirk Pranke, 2016-02-23 21:11:47]

lgtm

[Torne, 2016-02-24 18:08:49]

The CQ bit was checked by torne@chromium.org

[commit-bot: I haz the power, 2016-02-24 18:10:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1721763003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1721763003/1

[commit-bot: I haz the power, 2016-02-24 18:52:31]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-02-24 18:54:13]

Description was changed from

==========
Silence dpkg-query errors in install-build-deps.

On leading-edge Ubuntu versions there are no LTS backport packages, and
dpkg-query prints an error about nothing matching the wildcard to
stderr, which has caused at least one user to think the script didn't
install mesa correctly. The script handles this case just fine, though
(it expands to an empty array and sets mesa_variant to emptystring,
whcih is correct), so just redirect stderr to avoid this spurious error
message.

BUG=
==========

to

==========
Silence dpkg-query errors in install-build-deps.

On leading-edge Ubuntu versions there are no LTS backport packages, and
dpkg-query prints an error about nothing matching the wildcard to
stderr, which has caused at least one user to think the script didn't
install mesa correctly. The script handles this case just fine, though
(it expands to an empty array and sets mesa_variant to emptystring,
whcih is correct), so just redirect stderr to avoid this spurious error
message.

BUG=

Committed: https://crrev.com/12cd9f6cf09631a18f11f123cc02e753dfcaa199
Cr-Commit-Position: refs/heads/master@{#377332}
==========

[commit-bot: I haz the power, 2016-02-24 18:54:13]

Patchset 1 (id:??) landed as
https://crrev.com/12cd9f6cf09631a18f11f123cc02e753dfcaa199
Cr-Commit-Position: refs/heads/master@{#377332}