rpm: don't hardcode the binary paths in the macros, rely on $PATH

this gives us a little bit more freedom to move things around later on,
as we don't hardcode the systemd paths in old RPMs that shall work with
new systemds.

(cherry picked from commit 8cf7c96517)

src/core/macros.systemd.in

@@ -37,42 +37,42 @@ Requires(postun): systemd \
 %systemd_post() \
 if [ $1 -eq 1 ] ; then \
         # Initial installation \
-        @rootbindir@/systemctl preset %{?*} >/dev/null 2>&1 || : \
+        systemctl preset %{?*} >/dev/null 2>&1 || : \
 fi \
 %{nil}
 
 %systemd_preun() \
 if [ $1 -eq 0 ] ; then \
         # Package removal, not upgrade \
-        @rootbindir@/systemctl --no-reload disable %{?*} > /dev/null 2>&1 || : \
-        @rootbindir@/systemctl stop %{?*} > /dev/null 2>&1 || : \
+        systemctl --no-reload disable %{?*} > /dev/null 2>&1 || : \
+        systemctl stop %{?*} > /dev/null 2>&1 || : \
 fi \
 %{nil}
 
 %systemd_postun() \
-@rootbindir@/systemctl daemon-reload >/dev/null 2>&1 || : \
+systemctl daemon-reload >/dev/null 2>&1 || : \
 %{nil}
 
 %systemd_postun_with_restart() \
-@rootbindir@/systemctl daemon-reload >/dev/null 2>&1 || : \
+systemctl daemon-reload >/dev/null 2>&1 || : \
 if [ $1 -ge 1 ] ; then \
         # Package upgrade, not uninstall \
-        @rootbindir@/systemctl try-restart %{?*} >/dev/null 2>&1 || : \
+        systemctl try-restart %{?*} >/dev/null 2>&1 || : \
 fi \
 %{nil}
 
 %udev_hwdb_update() \
-@rootbindir@/udevadm hwdb --update >/dev/null 2>&1 || : \
+udevadm hwdb --update >/dev/null 2>&1 || : \
 %{nil}
 
 %udev_rules_update() \
-@rootbindir@/udevadm control --reload >/dev/null 2>&1 || : \
+udevadm control --reload >/dev/null 2>&1 || : \
 %{nil}
 
 %journal_catalog_update() \
-@rootbindir@/journalctl --update-catalog >/dev/null 2>&1 || : \
+journalctl --update-catalog >/dev/null 2>&1 || : \
 %{nil}
 
 %tmpfiles_create() \
-@rootbindir@/systemd-tmpfiles --create %{?*} >/dev/null 2>&1 || : \
+systemd-tmpfiles --create %{?*} >/dev/null 2>&1 || : \
 %{nil}