Fix undefined %{systemd_svcs} in RPM scriptlets

[loli10K]

Description

This allows RPM-based systems to properly control package installation and removal when using systemd. Without this change pre/post-install scripts will not work properly because the custom %{systemd_svcs} macro is not defined:

[root@centos zfs]# rpm -qp --scripts ./zfs-0.7.0-163_gdf1f129.el7.centos.x86_64.rpm 
postinstall scriptlet (using /bin/sh):

if [ $1 -eq 1 ] ; then 
        # Initial installation 
        systemctl preset %{systemd_svcs} >/dev/null 2>&1 || : 
fi 

exit 0
preuninstall scriptlet (using /bin/sh):

if [ $1 -eq 0 ] ; then 
        # Package removal, not upgrade 
        systemctl --no-reload disable %{systemd_svcs} > /dev/null 2>&1 || : 
        systemctl stop %{systemd_svcs} > /dev/null 2>&1 || : 
fi 

exit 0
postuninstall scriptlet (using /bin/sh):

systemctl daemon-reload >/dev/null 2>&1 || :
[root@centos zfs]# 

With patch applied:

[root@centos zfs]# rpm -qp --scripts ./zfs-0.7.0-163_gdf1f129.el7.centos.x86_64.rpm 
postinstall scriptlet (using /bin/sh):

if [ $1 -eq 1 ] ; then 
        # Initial installation 
        systemctl preset zfs-import-cache.service zfs-import-scan.service zfs-mount.service zfs-share.service zfs-zed.service zfs.target >/dev/null 2>&1 || : 
fi 

exit 0
preuninstall scriptlet (using /bin/sh):

if [ $1 -eq 0 ] ; then 
        # Package removal, not upgrade 
        systemctl --no-reload disable zfs-import-cache.service zfs-import-scan.service zfs-mount.service zfs-share.service zfs-zed.service zfs.target > /dev/null 2>&1 || : 
        systemctl stop zfs-import-cache.service zfs-import-scan.service zfs-mount.service zfs-share.service zfs-zed.service zfs.target > /dev/null 2>&1 || : 
fi 

exit 0
postuninstall scriptlet (using /bin/sh):

systemctl daemon-reload >/dev/null 2>&1 || :
[root@centos zfs]# 

Motivation and Context

Fix #6838

How Has This Been Tested?

Local build

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Performance enhancement (non-breaking change which improves efficiency)
• Code cleanup (non-breaking change which makes code smaller or more readable)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation (a change to man pages or other documentation)

Checklist:

• My code follows the ZFS on Linux code style requirements.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.
• All commit messages are properly formatted and contain Signed-off-by.
• Change has been approved by a ZFS on Linux member.

[behlendorf]

Nice fix.