ide: remove REQ_TYPE_ATA_TASK

Based on the earlier work by Tejun Heo.

All users are gone so we can finally remove it.

Cc: Tejun Heo <htejun@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/ide-lib.c b/drivers/ide/ide-lib.c
index 6dbf2af..3bae2c4 100644
--- a/drivers/ide/ide-lib.c
+++ b/drivers/ide/ide-lib.c
@@ -458,8 +458,7 @@
 	spin_unlock(&ide_lock);
 	if (!rq)
 		return;
-	if (rq->cmd_type == REQ_TYPE_ATA_CMD ||
-	    rq->cmd_type == REQ_TYPE_ATA_TASK) {
+	if (rq->cmd_type == REQ_TYPE_ATA_CMD) {
 		char *args = rq->buffer;
 		if (args) {
 			opcode = args[0];