packaging: correct rpm syntax

The "%postun -p /sbin/ldconfig" is only valid when there is only
one %post and/or %postun command, for multiple commands the '-p'
should not be used, as documented here:
https://fedoraproject.org/wiki/Packaging:Guidelines#Shared_Libraries

Change-Id: I3b6c0ef1bad942987e75767ade8e0efe507a91aa
Tuleap: #1545

packaging/rules/fedora/ring.spec

@@ -205,11 +205,10 @@ DESTDIR=%{buildroot} make -C client-gnome/build install
 %{_datadir}/dbus-1/interfaces/*
 
 %post
--p /sbin/ldconfig
+/sbin/ldconfig
 /bin/touch --no-create %{_datadir}/icons/hicolor &>/dev/null || :
 
-%postun
--p /sbin/ldconfig
+%postun -p /sbin/ldconfig
 
 #for < f24 we have to update the schema explicitly
 %if 0%{?fedora} < 24