[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/wdt977.c b/drivers/char/watchdog/wdt977.c
index a0935bc..6253041 100644
--- a/drivers/char/watchdog/wdt977.c
+++ b/drivers/char/watchdog/wdt977.c
@@ -361,7 +361,7 @@
 	switch(cmd)
 	{
 	default:
-		return -ENOIOCTLCMD;
+		return -ENOTTY;
 
 	case WDIOC_GETSUPPORT:
 		return copy_to_user(uarg.ident, &ident,