s390/sclp: use -EOPNOTSUPP instead of -ENOSYS

The return value was only internally used, so it's ok to change.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/char/sclp.c b/drivers/s390/char/sclp.c
index 3fcc000..4fa21f7 100644
--- a/drivers/s390/char/sclp.c
+++ b/drivers/s390/char/sclp.c
@@ -334,7 +334,7 @@
 			reg->receiver_fn(evbuf);
 			spin_lock_irqsave(&sclp_lock, flags);
 		} else if (reg == NULL)
-			rc = -ENOSYS;
+			rc = -EOPNOTSUPP;
 	}
 	spin_unlock_irqrestore(&sclp_lock, flags);
 	return rc;