volser: use OS_CLOSE() instead of close()

volser: use OS_CLOSE() instead of close()

Use OS_CLOSE() instead of close() when closing vol package
allocated file descriptors.  On Windows, close() != nt_close().

Reviewed-on: http://gerrit.openafs.org/3668
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
(cherry picked from commit ecf55b063e7c9bbbac426831dfe504c1db92bb52)

Change-Id: I40114c0cf071a18612bb1ed29d18ab145f466dec
Reviewed-on: http://gerrit.openafs.org/3830
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>