tpm_tis: further simplify calculation of ordinal duration

tpm_tis: further simplify calculation of ordinal duration

BugLink: http://bugs.launchpad.net/bugs/1398274
commit 07b133e6060b ("char/tpm: simplify duration calculation and
eliminate smatch warning.") includes a misleading test that is always
false. The tpm_ordinal_duration table is only valid for TPM_PROTECTED
ordinals where the higher 16 bits are all 0, anyway.

Signed-off-by: Martin Wilck <Martin.Wilck@ts.fujitsu.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Acked-by: Peter Huewe <peterhuewe@gmx.de>
(cherry picked from commit f728643001397cee39dcfabff6458a5fbc3baecf)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>