redhat: remove the openafs-kernel-version.sh script

redhat: remove the openafs-kernel-version.sh script

Commit ec706b21530240d7fb66bad2f08513eff8f7c335 (Remove Linux 2.4 compat
from RedHat packaging) removed the use of the script
openafs-kernel-version.sh, which was used in the linux 2.4 days to look
up the current kernel version.  Nowadays, we use the openafs-kmodtool
script to determine the kernel version.

Remove the unused openafs-kernel-version.sh script from the package
sources.

Reviewed-on: https://gerrit.openafs.org/12996
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
(cherry picked from commit 28ea20d03f8abd8109547d6825edad159748397a)

Change-Id: I8d85ad57e1202f190c1a88812b4532b9642597f5
Reviewed-on: https://gerrit.openafs.org/12999
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Tested-by: BuildBot <buildbot@rampaginggeek.com>