[PATCH] Fix up scsi_test_unit_ready() to work correctly with CD-ROMs

Olaf Hering noticed that SG_IO was no-longer working correctly on some
CD-ROMS.  The reason is a change in behaviour induced by switching to
the new scsi_test_unit_ready() API.

Apparently the CD-ROM special case needs to ignore both UNIT_ATTENTION
and NOT_READY for removable media.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/scsi_lib.c

@@ -1589,7 +1589,8 @@ scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries)
 	scsi_wait_req(sreq, cmd, NULL, 0, timeout, retries);
 
 	if ((driver_byte(sreq->sr_result) & DRIVER_SENSE) &&
-	    (sreq->sr_sense_buffer[2] & 0x0f) == UNIT_ATTENTION &&
+	    ((sreq->sr_sense_buffer[2] & 0x0f) == UNIT_ATTENTION ||
+	     (sreq->sr_sense_buffer[2] & 0x0f) == NOT_READY) &&
 	    sdev->removable) {
 		sdev->changed = 1;
 		sreq->sr_result = 0;