Use 'id' instead of 'whoami' to determine user identity

'whoami' is missing in some environment such as initramfs. Let's use
'id' instead.

BUG=chrome-os-partner:17368
TEST=Factory install.

Change-Id: Ibdbcd58f7759944616a3e08c8e5fded7ceeeca33
Signed-off-by: Vic Yang <victoryang@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/41919
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
1 file changed