s390/sclp: Suppress unnecessary Store Data warning

On systems that do not support Store Data events (such as when running
as KVM guest) the following warning message appears during boot:

 sclp_sd: Store Data request failed (eq=2, di=3, response=0x40f0,
          flags=0x00, status=0, rc=-5)

This warning does not add any useful information since the result is
expected due to missing support for that event type.

Suppress this message by checking the associated masks of supported
events before issuing a Store Data event.

Suggested-by: Heiko Carstens <[email protected]>
Reviewed-by: Heiko Carstens <[email protected]>
Signed-off-by: Peter Oberparleiter <[email protected]>
Signed-off-by: Alexander Gordeev <[email protected]>

Author: oberpar

drivers/s390/char/sclp_sd.c

@@ -194,6 +194,10 @@ static int sclp_sd_sync(unsigned long page, u8 eq, u8 di, u64 sat, u64 sa,
 	struct sclp_sd_evbuf *evbuf;
 	int rc;
 
+	if (!sclp_sd_register.sclp_send_mask ||
+	    !sclp_sd_register.sclp_receive_mask)
+		return -EIO;
+
 	sclp_sd_listener_init(&listener, __pa(sccb));
 	sclp_sd_listener_add(&listener);