drm/exynos: Use lockless gem BO free callback

No dev->struct_mutex anywhere to be seen.

Cc: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Acked-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1461691808-12414-18-git-send-email-daniel.vetter@ffwll.ch

drivers/gpu/drm/exynos/exynos_drm_drv.c

@@ -418,7 +418,7 @@ static struct drm_driver exynos_drm_driver = {
 	.get_vblank_counter	= drm_vblank_no_hw_counter,
 	.enable_vblank		= exynos_drm_crtc_enable_vblank,
 	.disable_vblank		= exynos_drm_crtc_disable_vblank,
-	.gem_free_object	= exynos_drm_gem_free_object,
+	.gem_free_object_unlocked = exynos_drm_gem_free_object,
 	.gem_vm_ops		= &exynos_drm_gem_vm_ops,
 	.dumb_create		= exynos_drm_gem_dumb_create,
 	.dumb_map_offset	= exynos_drm_gem_dumb_map_offset,