tpm: Check size of response before accessing data

Make sure that we have not received less bytes than what is indicated
in the header of the TPM response. Also, check the number of bytes in
the response before accessing its data.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkine@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkine@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkine@linux.intel.com>