xstat: cm xstat time values are 32 bit

xstat: cm xstat time values are 32 bit

The kernel space cm xstat time structures are implemented as 32
bit values in memory and on the wire.  Define the client side
xstat userspace structures as 32 bit time values as well to avoid
size mismatches on systems with native 64 bit time values.

Change-Id: I857ea48bf8e12ec006ef24affb2e65a105ce27bb
Reviewed-on: http://gerrit.openafs.org/5237
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@openafs.org>
Reviewed-by: Derrick Brashear <shadow@dementix.org>