build: move file deleting action from %files list to %install

build: move file deleting action from %files list to %install

When building libvirt rpms on rhel5, I got the following error:

    File must begin with "/": rm
    File must begin with "/": -f
    File must begin with "/": $RPM_BUILD_ROOT/etc/sysctl.d/libvirtd
    Installed (but unpackaged) file(s) found:
   /etc/sysctl.d/libvirtd

It is triggerd by the %files list of libvirt daemon:

    %if 0%{?fedora} >= 14 || 0%{?rhel} >= 6
    %config(noreplace) %{_prefix}/lib/sysctl.d/libvirtd.conf
    %else
    rm -f $RPM_BUILD_ROOT%{_prefix}/lib/sysctl.d/libvirtd.conf
    %endif

After checking document of rpm spec file, I think it would be better
to move the file deleting line from %files list to %install script.

Bug introduced in commit a1fd56c.
(cherry picked from commit daef7c9e9c5abef65e77116a1cabad37c0c0a897)