ide-cd: revert DMA mask test change

The change to require the DMA length to be only word-aligned was not
safe.

drivers/ide/ide-cd.c

@@ -1932,8 +1932,11 @@ static ide_startstop_t cdrom_do_block_pc(ide_drive_t *drive, struct request *rq)
 
 		/*
 		 * check if dma is safe
+		 *
+		 * NOTE! The "len" and "addr" checks should possibly have
+		 * separate masks.
 		 */
-		if ((rq->data_len & 3) || (addr & mask))
+		if ((rq->data_len & mask) || (addr & mask))
 			info->dma = 0;
 	}