tpm2: Handle failures better

tpm2: Handle failures better

The current TpmFail() implementation invokes longjmp() at the end
and crashes with a segmentation fault if setjmp() wasn't called before.
To avoid this we implement TpmSetFailureMode() that logs the failure and
sets the TPM into failure mode. Since NVRAM may set failure mode before
the CryptInit() is called, we need to make sure we don't reset the failure
mode variable in case CryptInit() succeeds. In this case we now call the
FAIL_NOCMD() macro.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>