RedHat: Use git-version in makesrpm.pl

RedHat: Use git-version in makesrpm.pl

We no longer have the OpenAFS version in the AM_INIT_AUTOMAKE. Get the
version from the equivalent AC_INIT version, which is determined by
running build-tools/git-version. So, run git-version to get the
version.

Change-Id: I5feb72ba35566315654ab88f2047be8a7ac6b40a
Reviewed-on: http://gerrit.openafs.org/2640
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>
(cherry picked from commit 346ccf51ddedadd7f6709276237c26b7871ffbaf)
Reviewed-on: http://gerrit.openafs.org/2691