Windows: osilog param size is size_t

Windows: osilog param size is size_t

The parameter size is size_t which permits pointers to be stored
on 32-bit and 64-bit systems.  Make sure we store it as size_t
instead of truncating to long.

Reviewed-on: http://gerrit.openafs.org/3657
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@openafs.org>
Tested-by: Jeffrey Altman <jaltman@openafs.org>
(cherry picked from commit e50cab06c4a5dad37b27f411dfd511130567726d)

Change-Id: Ifff3cc8d9424c74d39a792f83b838965af95faea
Reviewed-on: http://gerrit.openafs.org/3819
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>