can: mcp251xfd: mcp251xfd_probe(): use dev_err_probe() to simplify error handling

dev_err_probe() can reduce code size, uniform error handling and record the
defer probe reason etc., use it to simplify the code.

Link: https://lore.kernel.org/r/20210128104644.2982125-9-mkl@pengutronix.deSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c

@@ -2849,32 +2849,28 @@ static int mcp251xfd_probe(struct spi_device *spi)
 
 	rx_int = devm_gpiod_get_optional(&spi->dev, "microchip,rx-int",
 					 GPIOD_IN);
-	if (PTR_ERR(rx_int) == -EPROBE_DEFER)
-		return -EPROBE_DEFER;
-	else if (IS_ERR(rx_int))
-		return PTR_ERR(rx_int);
+	if (IS_ERR(rx_int))
+		return dev_err_probe(&spi->dev, PTR_ERR(rx_int),
+				     "Failed to get RX-INT!\n");
 
 	reg_vdd = devm_regulator_get_optional(&spi->dev, "vdd");
-	if (PTR_ERR(reg_vdd) == -EPROBE_DEFER)
-		return -EPROBE_DEFER;
-	else if (PTR_ERR(reg_vdd) == -ENODEV)
+	if (PTR_ERR(reg_vdd) == -ENODEV)
 		reg_vdd = NULL;
 	else if (IS_ERR(reg_vdd))
-		return PTR_ERR(reg_vdd);
+		return dev_err_probe(&spi->dev, PTR_ERR(reg_vdd),
+				     "Failed to get VDD regulator!\n");
 
 	reg_xceiver = devm_regulator_get_optional(&spi->dev, "xceiver");
-	if (PTR_ERR(reg_xceiver) == -EPROBE_DEFER)
-		return -EPROBE_DEFER;
-	else if (PTR_ERR(reg_xceiver) == -ENODEV)
+	if (PTR_ERR(reg_xceiver) == -ENODEV)
 		reg_xceiver = NULL;
 	else if (IS_ERR(reg_xceiver))
-		return PTR_ERR(reg_xceiver);
+		return dev_err_probe(&spi->dev, PTR_ERR(reg_xceiver),
+				     "Failed to get Transceiver regulator!\n");
 
 	clk = devm_clk_get(&spi->dev, NULL);
-	if (IS_ERR(clk)) {
-		dev_err(&spi->dev, "No Oscillator (clock) defined.\n");
-		return PTR_ERR(clk);
-	}
+	if (IS_ERR(clk))
+		dev_err_probe(&spi->dev, PTR_ERR(clk),
+			      "Failed to get Oscillator (clock)!\n");
 	freq = clk_get_rate(clk);
 
 	/* Sanity check */