cryptohome: look for flag file to determine if init pkcs11

Change-Id: Ie2a43c98852b390c2a9089ccbe9304d60651810b

BUG=none
TEST=
Try with secure_certificates on and off - verify successful boot, verify messages about
trying pkcs11 init when on.

Review URL: http://codereview.chromium.org/6883081
1 file changed