[Intel-gfx] [PATCH i-g-t] tests/kms_cursor_legacy: Use gem_mmap__gtt() rather than gem_mmap__wc()

[Chris Wilson]

Quoting Ville Syrjala (2017-09-20 17:35:05)
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> WC mmaps aren't universally supported, so let's not depend on them when
> any kind of mmap will do.

We can replace this code now with igt_spin_batch
https://patchwork.freedesktop.org/patch/176860/
-Chris