Currently it returns zero when CRQ response timed out, it should return
an error code instead.

Fixes: d8d74ea3 ("tpm: ibmvtpm: Wait for buffer to be set before proceeding")
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>