NOMMU re-exec trick shuld not depend on existence of "don't daemonize"

option for every affected applet (and dnsd, for example, don't have one).
Thus rework re-exec support to not require it. Code got smaller too.

sysklogd/klogd.c

@@ -51,7 +51,8 @@ int klogd_main(int argc, char **argv)
 
 	if (!(option_mask32 & OPT_FOREGROUND)) {
 #ifdef BB_NOMMU
-		vfork_daemon_rexec(0, 1, argc, argv, "-n");
+		if (!re_execed)
+			vfork_daemon_rexec(0, 1, argv);
 #else
 		bb_daemonize();
 #endif

sysklogd/syslogd.c

@@ -643,7 +643,8 @@ int syslogd_main(int argc, char **argv)
 
 	if (!(option_mask32 & OPT_nofork)) {
 #ifdef BB_NOMMU
-		vfork_daemon_rexec(0, 1, argc, argv, "-n");
+		if (!re_execed)
+			vfork_daemon_rexec(0, 1, argv);
 #else
 		bb_daemonize();
 #endif