RedHat: Change the defined initdir path to /etc/rc.d/init.d

RedHat: Change the defined initdir path to /etc/rc.d/init.d

On Red Hat systems, /etc/init.d is a symlink to /etc/rc.d/init.d.  We
should use the actual path for packaging the init scripts, to avoid
any issues with package verification.

Reviewed-on: http://gerrit.openafs.org/3625
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
(cherry picked from commit da912adbf1512702a17b8e381af3d0225875e67c)

Change-Id: Ib00275f873987700312b402d6fe0513ce96e9cf8
Reviewed-on: http://gerrit.openafs.org/3982
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>