[S390] dasd: use -EOPNOTSUPP instead of -ENOTSUPP

return value -ENOTSUPP is not valid in userspace context, use
-EOPNOTSUPP instead

Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>