drm/bridge: lt8912b: do not return negative values from .get_modes()

The .get_modes() hooks aren't supposed to return negative error
codes. Return 0 for no modes, whatever the reason.

Cc: Adrien Grassein <adrien.grassein@gmail.com>
Cc: stable@vger.kernel.org
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/dcdddcbcb64b6f6cdc55022ee50c10dee8ddbc3d.1709913674.git.jani.nikula@intel.comSigned-off-by: Jani Nikula <jani.nikula@intel.com>

drivers/gpu/drm/bridge/lontium-lt8912b.c

@@ -441,23 +441,21 @@ lt8912_connector_mode_valid(struct drm_connector *connector,
 static int lt8912_connector_get_modes(struct drm_connector *connector)
 {
 	const struct drm_edid *drm_edid;
-	int ret = -1;
-	int num = 0;
 	struct lt8912 *lt = connector_to_lt8912(connector);
 	u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
+	int ret, num;
 
 	drm_edid = drm_bridge_edid_read(lt->hdmi_port, connector);
 	drm_edid_connector_update(connector, drm_edid);
-	if (drm_edid) {
-		num = drm_edid_connector_add_modes(connector);
-	} else {
-		return ret;
-	}
+	if (!drm_edid)
+		return 0;
+
+	num = drm_edid_connector_add_modes(connector);
 
 	ret = drm_display_info_set_bus_formats(&connector->display_info,
 					       &bus_format, 1);
-	if (ret)
-		num = ret;
+	if (ret < 0)
+		num = 0;
 
 	drm_edid_free(drm_edid);
 	return num;