virsh: Offer only persistent domains for autostart

The 'autostart' command accepts only persistent domains. Make the
completer return only those.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

tools/virsh-domain.c

@@ -1037,7 +1037,7 @@ static const vshCmdInfo info_autostart[] = {
 };
 
 static const vshCmdOptDef opts_autostart[] = {
-    VIRSH_COMMON_OPT_DOMAIN_FULL(0),
+    VIRSH_COMMON_OPT_DOMAIN_FULL(VIR_CONNECT_LIST_DOMAINS_PERSISTENT),
     {.name = "disable",
      .type = VSH_OT_BOOL,
      .help = N_("disable autostarting")