tmpfiles: narrow scope of HAVE_SYSV_COMPAT condition for legacy.conf

That file contains a bunch of entries of which only some are related to SysV.
The rest are just "traditional APIs" that need to stay. In particular,
/var/lock a.k.a. /run/lock is used by many programs (LVM, iscsi, alsactl).
Similarly, the README about /var/log is something that should stay as long as
we have people migrating from older systems or using the copiuos documentation
that mentions /var/log/messages.txt on the Internet.

/var/lock/subsys is only used by sysvinit, and our code to support /forcefsck,
/fastboot, and /forcequotacheck is conditionalized on HAVE_SYSV_COMPAT, so
conditionalize those here on HAVE_SYSV_COMPAT too.

tmpfiles.d/legacy.conf.in

@@ -7,8 +7,9 @@
 
 # See tmpfiles.d(5) for details
 
-# These files are considered legacy and are unnecessary on legacy-free
-# systems.
+# The functionality provided by these files and directories has been replaced
+# by newer interfaces. Their use is discouraged on legacy-free systems. This
+# configuration is provided to maintain backward compatibility.
 
 d /run/lock 0755 root root -
 L /var/lock - - - - ../run/lock
@@ -16,15 +17,15 @@ L /var/lock - - - - ../run/lock
 L$ /var/log/README - - - - ../..{{DOC_DIR}}/README.logs
 {% endif %}
 
+{% if HAVE_SYSV_COMPAT %}
 # /run/lock/subsys is used for serializing SysV service execution, and
 # hence without use on SysV-less systems.
-
 d /run/lock/subsys 0755 root root -
 
 # /forcefsck, /fastboot and /forcequotacheck are deprecated in favor of the
 # kernel command line options 'fsck.mode=force', 'fsck.mode=skip' and
 # 'quotacheck.mode=force'
-
 r! /forcefsck
 r! /fastboot
 r! /forcequotacheck
+{% endif %}

tmpfiles.d/meson.build

@@ -35,7 +35,7 @@ in_files = [
         ['20-systemd-stub.conf',          'ENABLE_EFI'],
         ['20-systemd-userdb.conf',        'ENABLE_SSH_USERDB_CONFIG'],
         ['etc.conf'],
-        ['legacy.conf',                   'HAVE_SYSV_COMPAT'],
+        ['legacy.conf'],
         ['static-nodes-permissions.conf'],
         ['systemd.conf'],
         ['var.conf'],