pseudomodem: Cleanup VirtualEthernetInterface cleanup.

The cleanup is now done in the forked subprocess and one of the options
passed to dnsmasq has been changed. This ensures that no orphaned or zombie
dnsmasq processes remain once pseudomodem exits.

BUG=chromium:251498
TEST=Run pseudomodem both individually and as part of a test. There
should remain no processes that are running dnsmasq afterwards.

Change-Id: Ie3058c6d374d5fe40c0d0fab70383a920eeb5426
Reviewed-on: https://gerrit.chromium.org/gerrit/59136
Commit-Queue: Arman Uguray <armansito@chromium.org>
Reviewed-by: Arman Uguray <armansito@chromium.org>
Tested-by: Arman Uguray <armansito@chromium.org>
1 file changed