drm: rcar-du: Use %p4cc to print 4CC format

Use the %p4cc format specifier to print 4CCs, which will provide a more
readable message than the raw hex value.
Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

drivers/gpu/drm/rcar-du/rcar_du_kms.c

@@ -405,8 +405,8 @@ rcar_du_fb_create(struct drm_device *dev, struct drm_file *file_priv,
 
 	format = rcar_du_format_info(mode_cmd->pixel_format);
 	if (format == NULL) {
-		dev_dbg(dev->dev, "unsupported pixel format %08x\n",
-			mode_cmd->pixel_format);
+		dev_dbg(dev->dev, "unsupported pixel format %p4cc\n",
+			&mode_cmd->pixel_format);
 		return ERR_PTR(-EINVAL);
 	}
 

drivers/gpu/drm/rcar-du/rcar_du_plane.c

@@ -625,8 +625,8 @@ int __rcar_du_plane_atomic_check(struct drm_plane *plane,
 
 	*format = rcar_du_format_info(state->fb->format->format);
 	if (*format == NULL) {
-		dev_dbg(dev->dev, "%s: unsupported format %08x\n", __func__,
-			state->fb->format->format);
+		dev_dbg(dev->dev, "%s: unsupported format %p4cc\n", __func__,
+			&state->fb->format->format);
 		return -EINVAL;
 	}
 

drivers/gpu/drm/rcar-du/rcar_du_writeback.c

@@ -166,8 +166,8 @@ static int rcar_du_wb_enc_atomic_check(struct drm_encoder *encoder,
 
 	wb_state->format = rcar_du_format_info(fb->format->format);
 	if (wb_state->format == NULL) {
-		dev_dbg(dev->dev, "%s: unsupported format %08x\n", __func__,
-			fb->format->format);
+		dev_dbg(dev->dev, "%s: unsupported format %p4cc\n", __func__,
+			&fb->format->format);
 		return -EINVAL;
 	}