ide: remove ide_task_t typedef

While at it:
- rename struct ide_task_s to struct ide_cmd
- remove stale comments from idedisk_{read_native,set}_max_address()
- drop unused 'cmd' argument from ide_{cmd,task}_ioctl()
- drop unused 'task' argument from tx4939ide_tf_load_fixup()
- rename ide_complete_task() to ide_complete_cmd()
- use consistent naming for struct ide_cmd variables

There should be no functional changes caused by this patch.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/ide-proc.c b/drivers/ide/ide-proc.c
index 417cde5..10a88bf 100644
--- a/drivers/ide/ide-proc.c
+++ b/drivers/ide/ide-proc.c
@@ -194,20 +194,20 @@
 
 static int set_xfer_rate (ide_drive_t *drive, int arg)
 {
-	ide_task_t task;
+	struct ide_cmd cmd;
 	int err;
 
 	if (arg < XFER_PIO_0 || arg > XFER_UDMA_6)
 		return -EINVAL;
 
-	memset(&task, 0, sizeof(task));
-	task.tf.command = ATA_CMD_SET_FEATURES;
-	task.tf.feature = SETFEATURES_XFER;
-	task.tf.nsect   = (u8)arg;
-	task.tf_flags = IDE_TFLAG_OUT_FEATURE | IDE_TFLAG_OUT_NSECT |
-			IDE_TFLAG_IN_NSECT;
+	memset(&cmd, 0, sizeof(cmd));
+	cmd.tf.command = ATA_CMD_SET_FEATURES;
+	cmd.tf.feature = SETFEATURES_XFER;
+	cmd.tf.nsect   = (u8)arg;
+	cmd.tf_flags   = IDE_TFLAG_OUT_FEATURE | IDE_TFLAG_OUT_NSECT |
+			 IDE_TFLAG_IN_NSECT;
 
-	err = ide_no_data_taskfile(drive, &task);
+	err = ide_no_data_taskfile(drive, &cmd);
 
 	if (!err) {
 		ide_set_xfer_rate(drive, (u8) arg);