drm/sun4i: dsi: Make use of the helper function dev_err_probe()

When possible use dev_err_probe help to properly deal with the
PROBE_DEFER error, the benefit is that DEFER issue will be logged
in the devices_deferred debugfs file.
And using dev_err_probe() can reduce code size, the error value
gets printed.

Signed-off-by: Cai Huoqing <[e-mail]>
Signed-off-by: Maxime Ripard <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c

···
 	}
 
 	dsi->regulator = devm_regulator_get(dev, "vcc-dsi");
-	if (IS_ERR(dsi->regulator)) {
-		dev_err(dev, "Couldn't get VCC-DSI supply\n");
-		return PTR_ERR(dsi->regulator);
-	}
+	if (IS_ERR(dsi->regulator))
+		return dev_err_probe(dev, PTR_ERR(dsi->regulator),
+				     "Couldn't get VCC-DSI supply\n");
 
 	dsi->reset = devm_reset_control_get_shared(dev, NULL);
 	if (IS_ERR(dsi->reset)) {
···
 	}
 
 	dsi->bus_clk = devm_clk_get(dev, bus_clk_name);
-	if (IS_ERR(dsi->bus_clk)) {
-		dev_err(dev, "Couldn't get the DSI bus clock\n");
-		return PTR_ERR(dsi->bus_clk);
-	}
+	if (IS_ERR(dsi->bus_clk))
+		return dev_err_probe(dev, PTR_ERR(dsi->bus_clk),
+				     "Couldn't get the DSI bus clock\n");
 
 	ret = regmap_mmio_attach_clk(dsi->regs, dsi->bus_clk);
 	if (ret)