ldconfig: make %ldconfig_post/%ldconfig_postun parameterized
If %ldconfig is not defined, then "%ldconfig_post/%ldconfig_postun foo"
will expand to " foo" which is breaking packages.
Also now it is possible to move %end into post/postun.
Reported-by: Terje Røsten <terjeros@phys.ntnu.no>
References: https://bugzilla.redhat.com/show_bug.cgi?id=1548331
Signed-off-by: Igor Gnatenko <ignatenkobrain@fedoraproject.org>