drivers: gpu: drm: xen_drm_front_drm_info is declared twice

struct xen_drm_front_drm_info has been declared.
Remove the duplicate.
Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210325061901.851273-1-wanjiabing@vivo.com

drivers/gpu/drm/xen/xen_drm_front_conn.h

@@ -16,7 +16,6 @@
 struct drm_connector;
 struct xen_drm_front_drm_info;
 
-struct xen_drm_front_drm_info;
 
 int xen_drm_front_conn_init(struct xen_drm_front_drm_info *drm_info,
 			    struct drm_connector *connector);