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-lib.c b/drivers/ide/ide-lib.c
index 6857e6a..56ff8c4 100644
--- a/drivers/ide/ide-lib.c
+++ b/drivers/ide/ide-lib.c
@@ -79,7 +79,7 @@
 	} else
 		cmd.valid.in.tf  = IDE_VALID_LBA | IDE_VALID_DEVICE;
 
-	drive->hwif->tp_ops->tf_read(drive, &cmd);
+	ide_tf_readback(drive, &cmd);
 
 	if (lba48 || (tf->device & ATA_LBA))
 		printk(KERN_CONT ", LBAsect=%llu",