drm/i915: Simplify i915_gem_obj_ggtt_offset_view

Can use the new vma->is_ggtt to simplify the check and
remove the local variables.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Dave Gordon <david.s.gordon@intel.com>

drivers/gpu/drm/i915/i915_gem.c

@@ -5249,13 +5249,10 @@ u64 i915_gem_obj_offset(struct drm_i915_gem_object *o,
 u64 i915_gem_obj_ggtt_offset_view(struct drm_i915_gem_object *o,
 				  const struct i915_ggtt_view *view)
 {
-	struct drm_i915_private *dev_priv = to_i915(o->base.dev);
-	struct i915_ggtt *ggtt = &dev_priv->ggtt;
 	struct i915_vma *vma;
 
 	list_for_each_entry(vma, &o->vma_list, obj_link)
-		if (vma->vm == &ggtt->base &&
-		    i915_ggtt_view_equal(&vma->ggtt_view, view))
+		if (vma->is_ggtt && i915_ggtt_view_equal(&vma->ggtt_view, view))
 			return vma->node.start;
 
 	WARN(1, "global vma for this object not found. (view=%u)\n", view->type);