i915: fix freeing path for gem phys objects.

This off-by-one was pointed out by Jesse Barnes.

Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 96316fd..b15ee1f 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3364,7 +3364,7 @@
 {
 	int i;
 
-	for (i = 0; i < I915_MAX_PHYS_OBJECT; i++)
+	for (i = I915_GEM_PHYS_CURSOR_0; i <= I915_MAX_PHYS_OBJECT; i++)
 		i915_gem_free_phys_object(dev, i);
 }