drm/i915: Unconditionally get the fence reg when pinning scanout

We use i915_gem_object_get_fence_reg() to do LRU tracking of the fence
registers, so stop trying to be too clever when pinning the fb->obj.
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

drivers/gpu/drm/i915/intel_display.c

@@ -1474,8 +1474,7 @@ intel_pin_and_fence_fb_obj(struct drm_device *dev,
 	 * framebuffer compression.  For simplicity, we always install
 	 * a fence as the cost is not that onerous.
 	 */
-	if (obj_priv->fence_reg == I915_FENCE_REG_NONE &&
-	    obj_priv->tiling_mode != I915_TILING_NONE) {
+	if (obj_priv->tiling_mode != I915_TILING_NONE) {
 		ret = i915_gem_object_get_fence_reg(obj, false);
 		if (ret)
 			goto err_unpin;