exynos: use drmCloseBufferHandle

Instead of manually calling drmIoctl, use the equivalent function
from libdrm core.

Signed-off-by: Simon Ser <contact@emersion.fr>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>

exynos/exynos_drm.c

@@ -176,11 +176,7 @@ drm_public void exynos_bo_destroy(struct exynos_bo *bo)
 		munmap(bo->vaddr, bo->size);
 
 	if (bo->handle) {
-		struct drm_gem_close req = {
-			.handle = bo->handle,
-		};
-
-		drmIoctl(bo->dev->fd, DRM_IOCTL_GEM_CLOSE, &req);
+		drmCloseBufferHandle(bo->dev->fd, bo->handle);
 	}
 
 	free(bo);