redhat: exclude kpasswd from debuginfo processing

redhat: exclude kpasswd from debuginfo processing

While kpasswd was in the separate openafs-kpasswd package to avoid
clashing with the krb5 executable, openafs-debuginfo still conflicted
with krb5-debuginfo. Remove the x-bits from kpasswd in %install to
make debuginfo processing ignore it, and add them back in the %files
list. Make kapasswd a copy rather than a hard link to have it processed
in the usual way.

This is a 1.6-only change. On the master branch, this issue is fixed
by commit 4e3ceaccd9dc2b6e6a20e938d82af1ebaa2c43c8 which however
removes kpasswd altogether and is thus considered inapproriate for the
stable release series.

FIXES 131771

Change-Id: Icd940e3f5da133a98401c7a28ed6ee0c637bf602
Reviewed-on: http://gerrit.openafs.org/12128
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Tested-by: Stephan Wiesand <stephan.wiesand@desy.de>
Reviewed-by: Marcio Brito Barbosa <mbarbosa@sinenomine.net>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>