drm/i915: Wrap drm_gem_object_reference in i915_gem_object_get

Ultimately wraps kref_get(), so adopt its nomenclature for consistency
with other subsystems.

s/drm_gem_object_reference/i915_gem_object_get/

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1469005202-9659-5-git-send-email-chris@chris-wilson.co.uk
Reviewed-by: Dave Gordon <david.s.gordon@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1469017917-15134-4-git-send-email-chris@chris-wilson.co.uk
diff --git a/drivers/gpu/drm/i915/i915_gem_evict.c b/drivers/gpu/drm/i915/i915_gem_evict.c
index b1194c7..5610394 100644
--- a/drivers/gpu/drm/i915/i915_gem_evict.c
+++ b/drivers/gpu/drm/i915/i915_gem_evict.c
@@ -183,7 +183,7 @@
 				       exec_list);
 		if (drm_mm_scan_remove_block(&vma->node)) {
 			list_move(&vma->exec_list, &eviction_list);
-			drm_gem_object_reference(&vma->obj->base);
+			i915_gem_object_get(vma->obj);
 			continue;
 		}
 		list_del_init(&vma->exec_list);