rpm: add RPM macros to apply sysusers, sysctl, and binfmt drop-ins

With this in place RPMs can make sure that whatever they drop in is
immeidately applied, and not delayed until next reboot.

This also moves systemd-sysusers back to /usr/bin, since hardcoding the
path to /usr/lib in the macros would mean compatibility breaks in
future, should we turn sysusers into a command that is actually OK for
people to call directly. And given that that is quite likely to happen
(since it is useful to prepare images with its --root= switch), let's
just prepare for it.

Makefile.am

@@ -1782,7 +1782,7 @@ systemd_sysusers_LDADD = \
 	libsystemd-internal.la \
 	libsystemd-shared.la
 
-rootlibexec_PROGRAMS += \
+rootbin_PROGRAMS += \
 	systemd-sysusers
 
 nodist_systemunit_DATA += \

src/core/macros.systemd.in

@@ -26,7 +26,9 @@
 %_udevrulesdir @udevrulesdir@
 %_journalcatalogdir @catalogdir@
 %_tmpfilesdir @tmpfilesdir@
+%_sysusersdir @sysusersdir@
 %_sysctldir @sysctldir@
+%_binfmtdir @binfmtdir@
 
 %systemd_requires \
 Requires(post): systemd \
@@ -76,3 +78,15 @@ journalctl --update-catalog >/dev/null 2>&1 || : \
 %tmpfiles_create() \
 systemd-tmpfiles --create %{?*} >/dev/null 2>&1 || : \
 %{nil}
+
+%sysusers_create() \
+systemd-sysusers %{?*} >/dev/null 2>&1 || : \
+%{nil}
+
+%sysctl_apply() \
+@rootlibexecdir@/systemd-sysctl %{?*} >/dev/null 2>&1 || : \
+%{nil}
+
+%binfmt_apply() \
+@rootlibexecdir@/systemd-binfmt %{?*} >/dev/null 2>&1 || : \
+%{nil}

units/systemd-sysusers.service.in

@@ -19,4 +19,4 @@ ConditionNeedsUpdate=/etc
 [Service]
 Type=oneshot
 RemainAfterExit=yes
-ExecStart=@rootlibexecdir@/systemd-sysusers
+ExecStart=@rootbindir@/systemd-sysusers