vol: Don't always FDH_REALLYCLOSE on linktable ops

vol: Don't always FDH_REALLYCLOSE on linktable ops

If we dec a linktable entry or get a free tag from the link table,
there is no reason to FDH_REALLYCLOSE the linktable fd handle.
FDH_REALLYCLOSE is the same as FDH_CLOSE, except that it tells the
ihandle package that the file handle will not be used again soon. If
we dec a linktable entry or get a free tag, there is no reason to
think that, so just FDH_CLOSE the handle instead.

Change-Id: I5f48a78528a75b984201f9ee0563b142ef59baf9
Reviewed-on: http://gerrit.openafs.org/4903
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>