Revert "drm/radeon/kms: fix typo in r100_blit_copy"

commit d9ad77eb upstream.

This reverts commit 18b4fada.

This code was correct, apologies to anyone who noticed things broke.

revert contents are different due to another commit in between.

Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>