NOMMU: do not hide startup syscalls unless in -D mode

On NOMMU systems in "strace PROG" case, we have no way to attach to
the tracee before it calls execve unless in -D mode.  That is, the
first execve call is very likely to be missed, and setting
hide_log_until_execve just results to empty log.

* strace.c (init) [NOMMU_SYSTEM]: Do not set hide_log_until_execve
unless in -D mode.

strace.c

@@ -1797,7 +1797,8 @@ init(int argc, char *argv[])
 	 * in the startup_child() mode we kill the spawned process anyway.
 	 */
 	if (argv[0]) {
-		hide_log_until_execve = 1;
+		if (!NOMMU_SYSTEM || daemonized_tracer)
+			hide_log_until_execve = 1;
 		skip_one_b_execve = 1;
 		startup_child(argv);
 	}