drm/i915: remove superfluous i915_gem_object_free_mmap_offset call

This should already be handled by drm_gem_object_release, which is
called later on.

Cc: Chris Wilson <[email protected]>
Signed-off-by: Matthew Auld <[email protected]>
Reviewed-by: Chris Wilson <[email protected]>
Signed-off-by: Joonas Lahtinen <[email protected]>
Link: http://patchwork.freedesktop.org/patch/msgid/[email protected]

Author: matt-auld

drivers/gpu/drm/i915/i915_gem.c

@@ -4901,7 +4901,6 @@ void i915_gem_free_object(struct drm_gem_object *gem_obj)
 	if (discard_backing_storage(obj))
 		obj->madv = I915_MADV_DONTNEED;
 	i915_gem_object_put_pages(obj);
-	i915_gem_object_free_mmap_offset(obj);
 
 	BUG_ON(obj->pages);