Process all systemd services through the systemd scriptlets

This patch ensures that all systemd services are processed through the
systemd scriptlets, so that services are properly configured per the
preset file installed by the package.

Without this, zfs.target is set, but none of the services are enabled per
the preset file, meaning automounting filesystems and such won't work
out of the box.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Neal Gompa <ngompa13@gmail.com>
Closes #5356

rpm/generic/zfs.spec.in

@@ -39,6 +39,7 @@
 # Generic enable switch for systemd
 %if %{with systemd}
 %define _systemd 1
+%define systemd_svcs zfs-import-cache.service zfs-import-scan.service zfs-mount.service zfs-share.service zfs-zed.service zfs.target
 %endif
 
 # RHEL >= 7 comes with systemd
@@ -239,7 +240,7 @@ find %{?buildroot}%{_libdir} -name '*.la' -exec rm -f {} \;
 
 %post
 %if 0%{?_systemd}
-%systemd_post zfs.target
+%systemd_post %{systemd_svcs}
 %else
 if [ -x /sbin/chkconfig ]; then
     /sbin/chkconfig --add zfs-import
@@ -252,7 +253,7 @@ exit 0
 
 %preun
 %if 0%{?_systemd}
-%systemd_preun zfs.target
+%systemd_preun %{systemd_svcs}
 %else
 if [ $1 -eq 0 ] && [ -x /sbin/chkconfig ]; then
     /sbin/chkconfig --del zfs-import
@@ -265,7 +266,7 @@ exit 0
 
 %postun
 %if 0%{?_systemd}
-%systemd_postun zfs.target
+%systemd_postun %{systemd_svcs}
 %endif
 
 %files