Revert "drm/i915: Clean up associated VMAs on context destruction"

Revert "drm/i915: Clean up associated VMAs on context destruction"

This reverts commit cb6909275677e8078af067b40f972df9ad991ac3.

The patch was only a stop-gap measure that fixed half the problem - the
leak of the fbcon when restarting X. A complete solution required
releasing the VMA when the object itself was closed rather than rely on
file/process exit. The previous patches add the VMA tracking necessary
to do close them along with the object, context or file, and so the time
has come to remove the partial fix.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470293567-10811-28-git-send-email-chris@chris-wilson.co.uk