drm/i915: Delete unused, pointless i915_driver_firstopen.

Thanks to Hannes Eder for pointing out that this code was dead according to
sparse.
Signed-off-by: NEric Anholt <eric@anholt.net>
Signed-off-by: NDave Airlie <airlied@linux.ie>

drivers/gpu/drm/i915/i915_dma.c

@@ -1006,14 +1006,6 @@ void i915_master_destroy(struct drm_device *dev, struct drm_master *master)
 	master->driver_priv = NULL;
 }
 
-
-static int i915_driver_firstopen(struct drm_device *dev)
-{
-	if (drm_core_check_feature(dev, DRIVER_MODESET))
-		return 0;
-	return 0;
-}
-
 /**
  * i915_driver_load - setup chip and create an initial config
  * @dev: DRM device