systemctl/halt: drop support for calling in SysV init script

Traditionally, halt is called at the end of the init script on
reboot/shutdown. To support such usecase, previously we read the current
runlevel from utmp and set force flag on reboot/shutdown.

This drops the support for such the usecase.
Note, neither supported nor tested, but hopefully still the command can
be used in the end of the sysv init script by specifying -ff.

src/systemctl/systemctl-compat-halt.c

@@ -77,16 +77,11 @@ int halt_parse_argv(int argc, char *argv[]) {
                 {}
         };
 
-        int c, r, runlevel;
+        int c, r;
 
         assert(argc >= 0);
         assert(argv);
 
-        /* called in sysvinit system as last command in shutdown/reboot so this is always forceful */
-        if (utmp_get_runlevel(&runlevel, NULL) >= 0)
-                if (IN_SET(runlevel, '0', '6'))
-                        arg_force = 2;
-
         while ((c = getopt_long(argc, argv, "pfwdnih", options, NULL)) >= 0)
                 switch (c) {