tpm: silence an array overflow warning

We should check that we're within bounds first before checking that
"chip->active_banks[i] != TPM2_ALG_ERROR" so I've re-ordered the two
checks.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>