Use CrosRunCommand to find if cherrypy is available. Fixed bug in CrosRunCommand

Call CrosRunCommand instead of calling ssh directly to find if cherrypy
is available.
Also fix bug in CrosRunCommand. The retval returned was always 0.

BUG=None
TEST=Reproduced with small test cases.

Change-Id: I277416b1809eb7287a75bd224b4154f442132a52
Reviewed-on: https://chrome-internal-review.googlesource.com/161123
Reviewed-by: Han Shen <shenhan@google.com>
Tested-by: Luis Lozano <llozano@chromium.org>
Commit-Queue: Caroline Tice <cmtice@google.com>
2 files changed