[TTY]: Use tty_mode_ioctl() in network drivers.

We conciously make a change here - we permit mode and speed setting to
be done in things like SLIP mode. There isn't actually a technical
reason to disallow this. It's usually a silly thing to do but we can
do it and soemone might wish to do so.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ppp_synctty.c b/drivers/net/ppp_synctty.c
index ce64032..00e2fb4 100644
--- a/drivers/net/ppp_synctty.c
+++ b/drivers/net/ppp_synctty.c
@@ -349,16 +349,11 @@
 		err = 0;
 		break;
 
-	case TCGETS:
-	case TCGETA:
-		err = n_tty_ioctl(tty, file, cmd, arg);
-		break;
-
 	case TCFLSH:
 		/* flush our buffers and the serial port's buffer */
 		if (arg == TCIOFLUSH || arg == TCOFLUSH)
 			ppp_sync_flush_output(ap);
-		err = n_tty_ioctl(tty, file, cmd, arg);
+		err = tty_perform_flush(tty, arg);
 		break;
 
 	case FIONREAD:
@@ -369,7 +364,8 @@
 		break;
 
 	default:
-		err = -ENOIOCTLCMD;
+		err = tty_mode_ioctl(tty, file, cmd, arg);
+		break;
 	}
 
 	sp_put(ap);