ide: refactor tf_read() method

Simplify tf_read() method, making it deal only with 'struct ide_taskfile' and
the validity flags that the upper layer passes, and factoring out the code that
deals with the high order bytes into ide_tf_readback() to be called from the
only two functions interested, ide_complete_cmd() and ide_dump_sector().

This should stop the needless code duplication in this method and so make
it about twice smaller than it was; along with simplifying the setup for
the method call, this should save both time and space...

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index e71c72b..2ae02b8 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -90,7 +90,7 @@
 		cmd->hob.data = data[1];
 	}
 
-	tp_ops->tf_read(drive, cmd);
+	ide_tf_readback(drive, cmd);
 
 	if ((cmd->tf_flags & IDE_TFLAG_CUSTOM_HANDLER) &&
 	    tf_cmd == ATA_CMD_IDLEIMMEDIATE) {