crosutils/mod_for_factory_scripts: don't change VT on factory service stop

crosutils/mod_for_factory_scripts: don't change VT on factory service stop

In http://codereview.chromium.org/6567004 in order to help developers stopping
factory UI, we've added an "chvt 2". However changing foreground terminal may
hang when executing "shutdown -r" inside Wipe test.

Removing the "chvt" call solved this issue. The only side effect is that
developers executing "initctl stop factory" may end seeing a black scren - and
they need to hit Ctrl-Alt-F2 to get the console back.

BUG=chrome-os-partner:2631
TEST=build a factory image then verified following steps:
     (1) in VT2, do "initctl stop factory, then C-A-F2: screen changed to VT2.
     (2) Execute factory tests until Wipe: reboots immediately when X closed
     (3) Execute Reboot in HWID test: reboots immediately when 'reboot' is ACTIVE

Change-Id: Ib6f44a6ad07db08862929179d0fe21cbbcc2b22a

Committed: http://chrome-svn/viewvc/chromeos?view=rev&revision=c750ac2

[Nick Sanders, 2011-03-07 17:11:53]

lgtm

[Hung-Te, 2011-03-08 01:25:01]

deprecated by http://codereview.chromium.org/6621041.