[Fedora-packaging] Small change to Beware of RPath

[Toshio Kuratomi]

fabiand on IRC let me know that there's a minor change that could be
made to the Beware of RPath section of the Guidelines to make things
easier for packagers:

[10:23:07] <fabiand> regarding an wiki page i can not edit:
packaging:guidelines#beware_of_rpath
[10:23:57] <fabiand> it should be recommended to use %{_arch} not using
32 or 64 as a suffix for files in /etc/ld.so.conf, because it is easy to
use %{a_arch} but not easy to get 64 or 32

https://fedoraproject.org/wiki/Packaging:Guidelines#Beware_of_Rpath

It would change this:
{{{
If you are storing a library in a non-standard location (e.g.
/usr/lib/foo/), you should include a custom config file in
/etc/ld.so.conf.d/. For example, if I was putting 32 bit libraries of
libfoo in /usr/lib/foo, I would want to make a file called "foo32.conf"
in /etc/ld.so.conf.d/, which contained the following:

/usr/lib/foo

Make sure that you also make a 64bit version of this file (e.g.
foo64.conf) as well (unless the package is disabled for 64bit
architectures, of course).
}}}

To this::
{{{
If you are storing a library in a non-standard location (e.g.
%{_libdir}/foo/), you should include a custom config file in
/etc/ld.so.conf.d/. For example, if I was putting 32 bit libraries of
libfoo in /usr/lib/foo and 64 bit libraries in /usr/lib64/foo I would
want to make a file called "foo%{_arch}.conf" in /etc/ld.so.conf.d/,
which contained the following on 32 bit:

/usr/lib/foo

and on 64 bit:
/usr/lib64/foo

That could be done in the specfile with
echo %{_libdir}/foo >
%{buildroot}%{_sysconfdir}/ld.so.conf.d/foo%{_arch}.conf
}}}

If this looks like a good change I'll put it on the agenda for the next
meeting.

-Toshio