Drop all mention of old fallback shell from comments

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

src/getty.c

@@ -189,8 +189,8 @@ static int do_login(char *name)
 	execl(_PATH_LOGIN, _PATH_LOGIN, name, NULL);
 
 	/*
-	 * Failed to exec login, should be impossible.  Try a starting a
-	 * fallback shell instead.
+	 * Failed to exec login, should not happen on normal systems.
+	 * Try a starting a rescue shell instead.
 	 *
 	 * Note: Add /etc/securetty handling.
 	 */

src/svc.c

@@ -433,7 +433,7 @@ svc_t *svc_find_by_tty(char *dev)
 {
 	svc_t *svc, *iter = NULL;
 
-	/* this is valid for fallback (notty) shells */
+	/* rescue (notty) shells have no device node */
 	if (!dev)
 		return NULL;
 

src/tty.c

@@ -158,7 +158,7 @@ int tty_parse_args(char *cmd, struct tty *tty)
 		else if (!strcmp(cmd, "nologin"))
 			tty->nologin = 1;
 		else if (!strcmp(cmd, "notty"))
-			tty->notty = 1;	/* for fallback shell */
+			tty->notty = 1;	/* for rescue shells */
 		else if (!access(cmd, X_OK))
 			tty->cmd = cmd;
 		else