[WATCHDOG] use ENOTTY instead of ENOIOCTLCMD in ioctl()

Return ENOTTY instead of ENOIOCTLCMD in user-visible ioctl() results

The watchdog drivers used to return ENOIOCTLCMD for bad ioctl() commands.
ENOIOCTLCMD should not be visible by the user, so use ENOTTY instead.

Signed-off-by: Samuel Tardieu <sam@rfc1149.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>

diff --git a/drivers/char/watchdog/i6300esb.c b/drivers/char/watchdog/i6300esb.c
index 870539e..fb64df4 100644
--- a/drivers/char/watchdog/i6300esb.c
+++ b/drivers/char/watchdog/i6300esb.c
@@ -315,7 +315,7 @@
                         return put_user(heartbeat, p);
 
                 default:
-                        return -ENOIOCTLCMD;
+                        return -ENOTTY;
         }
 }