Fix TpmIsReady regression.

To test:
1. Clear the TPM, reboot.  Run cryptohome --action=tpm_status.  It will return not ready until the TPM is owned, at which point it should show the TPM as enabled, owned, and ready.
2. Reboot after owning the TPM, run cryptohome --action=tpm_status.  It should show the TPM as enabled, owned, and ready.
3. Reboot after clearing the TPM in the bios, but not activating it.  It should show the TPM as not enabled, owned, or ready.

Change-Id: I352cc049866fa10c7b902f1de934d99394c904cc

BUG=none
TEST=manual

Review URL: http://codereview.chromium.org/3674006
1 file changed