scsi: xen-scsifront: Call scsi_done() directly

Conditional statements are faster than indirect calls. Hence call
scsi_done() directly.

Link: https://lore.kernel.org/r/[e-mail]
Reviewed-by: Juergen Gross <[e-mail]>
Signed-off-by: Bart Van Assche <[e-mail]>
Signed-off-by: Martin K. Petersen <[e-mail]>

drivers/scsi/xen-scsifront.c

···
 	if (sense_len)
 		memcpy(sc->sense_buffer, ring_rsp->sense_buffer, sense_len);
 
-	sc->scsi_done(sc);
+	scsi_done(sc);
 }
 
 static void scsifront_sync_cmd_done(struct vscsifrnt_info *info,
···
 		if (err == -ENOMEM)
 			return SCSI_MLQUEUE_HOST_BUSY;
 		sc->result = DID_ERROR << 16;
-		sc->scsi_done(sc);
+		scsi_done(sc);
 		return 0;
 	}