ide: move command related fields from ide_hwif_t to struct ide_cmd

* Move command related fields from ide_hwif_t to struct ide_cmd.

* Make ide_init_sg_cmd() take command and sectors number as arguments.

There should be no functional changes caused by this patch.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/ide-disk.c b/drivers/ide/ide-disk.c
index f1555dd..d00d807 100644
--- a/drivers/ide/ide-disk.c
+++ b/drivers/ide/ide-disk.c
@@ -104,14 +104,14 @@
 			lba48 = 0;
 	}
 
-	if (!dma) {
-		ide_init_sg_cmd(drive, rq);
-		ide_map_sg(drive, rq);
-	}
-
 	memset(&cmd, 0, sizeof(cmd));
 	cmd.tf_flags = IDE_TFLAG_TF | IDE_TFLAG_DEVICE;
 
+	if (dma == 0) {
+		ide_init_sg_cmd(&cmd, nsectors);
+		ide_map_sg(drive, rq);
+	}
+
 	if (drive->dev_flags & IDE_DFLAG_LBA) {
 		if (lba48) {
 			pr_debug("%s: LBA=0x%012llx\n", drive->name,
@@ -170,7 +170,7 @@
 		/* fallback to PIO */
 		cmd.tf_flags |= IDE_TFLAG_DMA_PIO_FALLBACK;
 		ide_tf_set_cmd(drive, &cmd, 0);
-		ide_init_sg_cmd(drive, rq);
+		ide_init_sg_cmd(&cmd, nsectors);
 		rc = do_rw_taskfile(drive, &cmd);
 	}