libata: use the WRITE_SAME_16 define

Now that the scsi tree has hit mainline we can use the newly added WRITE_SAME_16
define.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

drivers/ata/libata-scsi.c

@@ -3022,7 +3022,7 @@ static inline ata_xlat_func_t ata_get_xlat_func(struct ata_device *dev, u8 cmd)
 	case WRITE_16:
 		return ata_scsi_rw_xlat;
 
-	case 0x93 /*WRITE_SAME_16*/:
+	case WRITE_SAME_16:
 		return ata_scsi_write_same_xlat;
 
 	case SYNCHRONIZE_CACHE: