drm/i915: Demote i915_gem_open() debugging from DRIVER to USER

We use DRM_DEBUG() when reporting on user actions, to try and keep
intentional errors out of the CI dmesg. Demote the debug from
i915_gem_open() similarly so that it is only apparent with drm.debug & 1
like its brethren.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20161109104507.21228-1-chris@chris-wilson.co.ukReviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

drivers/gpu/drm/i915/i915_gem.c

@@ -4639,7 +4639,7 @@ int i915_gem_open(struct drm_device *dev, struct drm_file *file)
 	struct drm_i915_file_private *file_priv;
 	int ret;
 
-	DRM_DEBUG_DRIVER("\n");
+	DRM_DEBUG("\n");
 
 	file_priv = kzalloc(sizeof(*file_priv), GFP_KERNEL);
 	if (!file_priv)