scsi-generic: remove superfluous DPRINTF avoid to break compiling

variables lun and tag had been eliminated, break compiling
when enable debug switch. Meanwhile traces provide the same
information with this DPRINTF, so remove it.
Signed-off-by: NGonglei <arei.gonglei@huawei.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

hw/scsi/scsi-generic.c

@@ -303,9 +303,6 @@ static int32_t scsi_send_command(SCSIRequest *req, uint8_t *cmd)
     SCSIDevice *s = r->req.dev;
     int ret;
 
-    DPRINTF("Command: lun=%d tag=0x%x len %zd data=0x%02x", lun, tag,
-            r->req.cmd.xfer, cmd[0]);
-
 #ifdef DEBUG_SCSI
     {
         int i;