drm: bridge: adv7511: use dev_err_probe in probe function

adv7511 probe may need to be attempted multiple times before no
-EPROBE_DEFER is returned. Currently, every such probe results in
an error message:

[    4.534229] adv7511 1-003d: failed to find dsi host
[    4.580288] adv7511 1-003d: failed to find dsi host

This is misleading, as there is no error and probe deferral is normal
behavior. Fix this by using dev_err_probe that will suppress
-EPROBE_DEFER errors. While at it, we touch all dev_err in the probe
path. This makes the code more concise and included the error code
everywhere to aid user in debugging.
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20221026125246.3188260-1-a.fatoum@pengutronix.de

drivers/gpu/drm/bridge/adv7511/adv7511_drv.c

@@ -1219,10 +1219,8 @@ static int adv7511_probe(struct i2c_client *i2c, const struct i2c_device_id *id)
 		return ret;
 
 	ret = adv7511_init_regulators(adv7511);
-	if (ret) {
-		dev_err(dev, "failed to init regulators\n");
-		return ret;
-	}
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to init regulators\n");
 
 	/*
 	 * The power down GPIO is optional. If present, toggle it from active to

drivers/gpu/drm/bridge/adv7511/adv7533.c

@@ -149,16 +149,14 @@ int adv7533_attach_dsi(struct adv7511 *adv)
 						 };
 
 	host = of_find_mipi_dsi_host_by_node(adv->host_node);
-	if (!host) {
-		dev_err(dev, "failed to find dsi host\n");
-		return -EPROBE_DEFER;
-	}
+	if (!host)
+		return dev_err_probe(dev, -EPROBE_DEFER,
+				     "failed to find dsi host\n");
 
 	dsi = devm_mipi_dsi_device_register_full(dev, host, &info);
-	if (IS_ERR(dsi)) {
-		dev_err(dev, "failed to create dsi device\n");
-		return PTR_ERR(dsi);
-	}
+	if (IS_ERR(dsi))
+		return dev_err_probe(dev, PTR_ERR(dsi),
+				     "failed to create dsi device\n");
 
 	adv->dsi = dsi;
 
@@ -168,10 +166,8 @@ int adv7533_attach_dsi(struct adv7511 *adv)
 			  MIPI_DSI_MODE_NO_EOT_PACKET | MIPI_DSI_MODE_VIDEO_HSE;
 
 	ret = devm_mipi_dsi_attach(dev, dsi);
-	if (ret < 0) {
-		dev_err(dev, "failed to attach dsi to host\n");
-		return ret;
-	}
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "failed to attach dsi to host\n");
 
 	return 0;
 }