cpu-set-util: introduce config_parse_cpu_set()

Then, make parse_cpu_set() as a tiny wrapper of it.

Note, previously when an invalid CPU range, e.g. "3-0", is specified,
we ignore the range but allocate an empty set. But, with this commit,
now the conf parser simply ignore it without no side effect.
This potentially changes behavior of a system with such invalid setting,
but the change should be favorable for consistency with other parsers.

src/nspawn/nspawn-gperf.gperf

@@ -55,7 +55,7 @@ Exec.LimitRTTIME,             config_parse_rlimit,         RLIMIT_RTTIME,
 Exec.Hostname,                config_parse_hostname,       0,                        offsetof(Settings, hostname)
 Exec.NoNewPrivileges,         config_parse_tristate,       0,                        offsetof(Settings, no_new_privileges)
 Exec.OOMScoreAdjust,          config_parse_oom_score_adjust, 0,                      0
-Exec.CPUAffinity,             config_parse_cpu_affinity,   0,                        0
+Exec.CPUAffinity,             config_parse_cpu_set,        0,                        offsetof(Settings, cpu_set)
 Exec.ResolvConf,              config_parse_resolv_conf,    0,                        offsetof(Settings, resolv_conf)
 Exec.LinkJournal,             config_parse_link_journal,   0,                        0
 Exec.Timezone,                config_parse_timezone_mode,  0,                        offsetof(Settings, timezone)

src/nspawn/nspawn-settings.c

@@ -817,25 +817,6 @@ int config_parse_oom_score_adjust(
         return 0;
 }
 
-int config_parse_cpu_affinity(
-                const char *unit,
-                const char *filename,
-                unsigned line,
-                const char *section,
-                unsigned section_line,
-                const char *lvalue,
-                int ltype,
-                const char *rvalue,
-                void *data,
-                void *userdata) {
-
-        Settings *settings = ASSERT_PTR(data);
-
-        assert(rvalue);
-
-        return parse_cpu_set_extend(rvalue, &settings->cpu_set, true, unit, filename, line, lvalue);
-}
-
 DEFINE_CONFIG_PARSE_ENUM(config_parse_resolv_conf, resolv_conf_mode, ResolvConfMode);
 
 static const char *const resolv_conf_mode_table[_RESOLV_CONF_MODE_MAX] = {

src/nspawn/nspawn-settings.h

@@ -264,7 +264,6 @@ CONFIG_PARSER_PROTOTYPE(config_parse_pid2);
 CONFIG_PARSER_PROTOTYPE(config_parse_private_users);
 CONFIG_PARSER_PROTOTYPE(config_parse_syscall_filter);
 CONFIG_PARSER_PROTOTYPE(config_parse_oom_score_adjust);
-CONFIG_PARSER_PROTOTYPE(config_parse_cpu_affinity);
 CONFIG_PARSER_PROTOTYPE(config_parse_resolv_conf);
 CONFIG_PARSER_PROTOTYPE(config_parse_link_journal);
 CONFIG_PARSER_PROTOTYPE(config_parse_timezone_mode);