Chromoting Linux host: Replace subprocess.Popen() with subprocess.call()

Chromoting Linux host: Replace subprocess.Popen() with subprocess.call()

subprocess.call() is documented as accepting the same arguments as
subprocess.Popen(). This lets us simplify some usages.

NOTRY=true

Committed: https://crrev.com/1492c3d296476fe127c56fc889571f33cc59da43
Cr-Commit-Position: refs/heads/master@{#302630}

[Lambros, 2014-11-04 01:54:31]

lambroslambrou@chromium.org changed reviewers:
+ jamiewalch@chromium.org

[Jamie, 2014-11-04 02:49:57]

lgtm

[Lambros, 2014-11-04 18:30:12]

The CQ bit was checked by lambroslambrou@chromium.org

[commit-bot: I haz the power, 2014-11-04 18:31:41]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/698103003/1

[commit-bot: I haz the power, 2014-11-04 18:32:31]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-11-04 18:33:20]

Patchset 1 (id:??) landed as
https://crrev.com/1492c3d296476fe127c56fc889571f33cc59da43
Cr-Commit-Position: refs/heads/master@{#302630}