staging: Fix typo in winbond

Correct spelling typo in winbond/mto.c and mds_s.h

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>