drm/xe: Fix loop in vm_bind_ioctl_ops_unwind

The logic for the unwind loop is incorrect resulting in an infinite
loop. Fix to unwind to go from the last operations list to he first.

Fixes: 617eebb9

 ("drm/xe: Fix array of binds")
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240201175532.2303168-1-matthew.brost@intel.com