use macros for ldconfig

libidn.spec

@@ -22,9 +22,8 @@ BuildRequires: emacs
 %endif
 BuildRequires: pkgconfig
 BuildRequires: help2man
-Requires(post): /sbin/install-info /sbin/ldconfig
+Requires(post): /sbin/install-info
 Requires(preun): /sbin/install-info
-Requires(postun): /sbin/ldconfig
 # gnulib is a copylib, bundling is allowed
 Provides: bundled(gnulib)
 %if %{with libidn_enables_emacs}
@@ -160,14 +159,14 @@ rm -rf $RPM_BUILD_ROOT%{_javadir}/libidn*.jar
 
 %post
 /sbin/install-info %{_infodir}/%{name}.info.gz %{_infodir}/dir
-/sbin/ldconfig
+%?ldconfig
 
 %preun
 if [ $1 = 0 ]; then
     /sbin/install-info --delete %{_infodir}/%{name}.info.gz %{_infodir}/dir || :
 fi
 
-%postun -p /sbin/ldconfig
+%ldconfig_postun
 
 %files -f %{name}.lang
 %{!?_licensedir:%global license %%doc}