Improve "waiter" parameter description as discussed in param-audit.

bin/varnishd/mgt/mgt_param.c

@@ -1052,8 +1052,8 @@ static const struct parspec input_parspec[] = {
 		"off", "bool" },
 	{ "waiter", tweak_waiter, NULL, 0, 0,
 		"Select the waiter kernel interface.\n",
-		EXPERIMENTAL | MUST_RESTART,
-		"default", NULL },
+		WIZARD | MUST_RESTART,
+		WAITER_DEFAULT, NULL },
 	{ "diag_bitmap", tweak_diag_bitmap, 0, 0, 0,
 		"Bitmap controlling diagnostics code:\n"
 		"  0x00000001 - CNT_Session states.\n"

bin/varnishd/waiter/mgt_waiter.c

@@ -68,14 +68,14 @@ WAIT_tweak_waiter(struct cli *cli, const char *arg)
 		else
 			VCLI_Out(cli, "%s", waiter->name);
 
-		VCLI_Out(cli, " (");
+		VCLI_Out(cli, " (possible values: ");
 		for (i = 0; vca_waiters[i] != NULL; i++)
 			VCLI_Out(cli, "%s%s", i == 0 ? "" : ", ",
 			    vca_waiters[i]->name);
 		VCLI_Out(cli, ")");
 		return;
 	}
-	if (!strcmp(arg, "default")) {
+	if (!strcmp(arg, WAITER_DEFAULT)) {
 		waiter = vca_waiters[0];
 		return;
 	}

bin/varnishd/waiter/waiter.h

@@ -33,6 +33,8 @@ struct sess;
 typedef void* waiter_init_f(void);
 typedef void waiter_pass_f(void *priv, const struct sess *);
 
+#define WAITER_DEFAULT		"platform dependent"
+
 struct waiter {
 	const char		*name;
 	waiter_init_f		*init;

bin/varnishtest/tests/b00008.vtc

@@ -30,7 +30,7 @@ varnish v1 -start
 
 varnish v1 -cliok "help"
 
-varnish v1 -cliok "param.set waiter default"
+varnish v1 -cliok "param.set waiter poll"
 
 varnish v1 -clierr 106 "param.set waiter HASH(0x8839c4c)"