redhat: PACKAGE_VERSION macro no longer exists

redhat: PACKAGE_VERSION macro no longer exists

Commit 0d0e7699c9f789214205fe6837cded1a4c95f9c0 replaced all uses
of the %PACKAGE_VERSION macro in the spec with the %version one, but
missed an instance in the kmodtool script. Fix this, to avoid a
warning during rpmbuild.

Reviewed-on: https://gerrit.openafs.org/13031
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
(cherry picked from commit cfa74883e4996dfee2bd6ffaa3b967e5a7941e0b)

Change-Id: I2d57ddc3700f509da3255df1f952f55d8cd7f0e8
Reviewed-on: https://gerrit.openafs.org/13037
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>