consoles: switch to int put_char method

diff -u --new-file --recursive --exclude-from /usr/src/exclude linux.vanilla-2.6.25-rc8-mm2/drivers/char/viocons.c linux-2.6.25-rc8-mm2/drivers/char/viocons.c
@@ -628,13 +628,13 @@
 /*
  * TTY put_char method
  */
-static void viotty_put_char(struct tty_struct *tty, unsigned char ch)
+static int viotty_put_char(struct tty_struct *tty, unsigned char ch)
 {
 	struct port_info *pi;
 
 	pi = get_port_data(tty);
 	if (pi == NULL)
-		return;
+		return 0;
 
 	/* This will append '\r' as well if the char is '\n' */
 	if (viochar_is_console(pi))

@@ -642,6 +642,7 @@
 
 	if (viopath_isactive(pi->lp))
 		internal_write(pi, &ch, 1);
+	return 1;
 }
 
 /*

diff -u --new-file --recursive --exclude-from /usr/src/exclude linux.vanilla-2.6.25-rc8-mm2/drivers/char/vt.c linux-2.6.25-rc8-mm2/drivers/char/vt.c
@@ -2641,11 +2641,11 @@
 	return retval;
 }
 
-static void con_put_char(struct tty_struct *tty, unsigned char ch)
+static int con_put_char(struct tty_struct *tty, unsigned char ch)
 {
 	if (in_interrupt())
-		return;	/* n_r3964 calls put_char() from interrupt context */
-	do_con_write(tty, &ch, 1);
+		return 0;	/* n_r3964 calls put_char() from interrupt context */
+	return do_con_write(tty, &ch, 1);
 }
 
 static int con_write_room(struct tty_struct *tty)