drm/bridge: synopsys: dw-mipi-dsi: Remove a redundant check on existence of bridge->encoder

In the dw_mipi_dsi_bridge_attach() function, the check on the existence
of bridge->encoder is not necessary, as it has already been checked in
the drm_bridge_attach() function invocked by previous bridge or KMS driver.
The previous drm_bridge_attach() will quit with a negative error code
returned if it fails for some reasons, hence, it is guaranteed that the
.encoder member of the struct drm_bridge is not NULL when
dw_mipi_dsi_bridge_attach() function gets called.

Remove the redundant checking codes "if (!bridge->encoder) { ... }".
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Sui Jingfeng <sui.jingfeng@linux.dev>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240513153109.46786-10-sui.jingfeng@linux.dev

drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c

@@ -1071,11 +1071,6 @@ static int dw_mipi_dsi_bridge_attach(struct drm_bridge *bridge,
 {
 	struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge);
 
-	if (!bridge->encoder) {
-		DRM_ERROR("Parent encoder object not found\n");
-		return -ENODEV;
-	}
-
 	/* Set the encoder type as caller does not know it */
 	bridge->encoder->encoder_type = DRM_MODE_ENCODER_DSI;