Change tty default baud rate: 38400 -> 0, i.e. keep kernel default

This is a more sane default, and also what systems expect, and what
other getty implementations support.  I.e., unless specified, or set
to 0, the tty baud rate is zero -- which means do not change speed
at all.

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

src/exec.c

@@ -369,15 +369,12 @@ pid_t run_getty(char *tty, char *baud, char *term, int noclear, int nowait, stru
 
 	pid = fork();
 	if (!pid) {
-		speed_t speed = B38400;
-
-		if (baud && baud[0]) {
-			speed = stty_parse_speed(baud);
-			if (B0 == speed)
-				logit(LOG_CRIT, "TTY %s: Invalid speed %s", tty, baud);
-		}
+		speed_t speed;
 
+		speed = stty_parse_speed(baud);
+		logit(LOG_INFO, "Starting built-in getty on %s, speed %u", tty, speed);
 		prepare_tty(tty, speed, "tty", rlimit);
+
 		if (activate_console(noclear, nowait))
 			_exit(getty(tty, speed, term, NULL));
 	}
@@ -415,6 +412,7 @@ pid_t run_getty2(char *tty, char *cmd, char *args[], int noclear, int nowait, st
 		dup2(fd, STDERR_FILENO);
 
 		/* Dunno speed, tell stty() to not mess with it */
+		logit(LOG_INFO, "Starting external getty on %s, speed %u", tty, B0);
 		prepare_tty(tty, B0, "getty", rlimit);
 
 		if (ioctl(STDIN_FILENO, TIOCSCTTY, 1) < 0)

src/stty.c

@@ -27,6 +27,7 @@
 #include <sys/ttydefaults.h>  /* Not included by default in musl libc */
 #include <termios.h>
 
+/* B0 means; keep kernel default */
 speed_t stty_parse_speed(char *baud)
 {
 	char *ptr;
@@ -66,6 +67,9 @@ speed_t stty_parse_speed(char *baud)
 		{ 4000000, B4000000 },
 	};
 
+	if (!baud || !baud[0])
+		return B0;
+
 	errno = 0;
 	val = strtoul(baud, &ptr, 10);
 	if (errno || ptr == baud)