DARWIN: replace macro exported by automake

Commit 4706854f57043c8393baa922dd1974176e110a19 removed automake
references from the source tree. As a result, VERSION (exported by
AM_INIT_AUTOMAKE and obtained from Autoconf's AC_INIT macro) is not
available anymore. Unfortunately, a reference to this macro can be found
in src/afs/DARWIN/osi_module.c. Consequently, builds on OS X fail with
the following message:

    osi_module.c:144:32: error: use of undeclared identifier 'VERSION'

To fix this problem, replace VERSION by PACKAGE_VERSION (defined by
AC_INIT).

Reviewed-on: https://gerrit.openafs.org/13354
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
(cherry picked from commit 07ed94cfd817dc5a4e2d2712570087388fe7828f)

Change-Id: I14c6c803766ea959dfc6fa4804960c067fc9f16c
Reviewed-on: https://gerrit.openafs.org/13584
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Reviewed-by: Cheyenne Wills <cwills@sinenomine.net>
Reviewed-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Marcio Brito Barbosa <mbarbosa@sinenomine.net>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>

src/afs/DARWIN/osi_module.c

@@ -141,5 +141,5 @@ afs_modunload(struct kmod_info * kmod_info, void *data)
     return KERN_SUCCESS;
 }
 
-KMOD_EXPLICIT_DECL(MYBUNDLEID, VERSION, afs_modload,
+KMOD_EXPLICIT_DECL(MYBUNDLEID, PACKAGE_VERSION, afs_modload,
 		   afs_modunload)