iio: imu: inv_mpu6050_spi: Use vsprintf extension %pe for symbolic error name

Utilize %pe format specifier from vsprintf while printing error logs
with dev_err(). Discards the use of unnecessary explicit casting and
prints symbolic error name which might prove to be convenient during
debugging.

Signed-off-by: Nishant Malpani <nish.malpani25@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/imu/inv_mpu6050/inv_mpu_spi.c

@@ -53,8 +53,8 @@ static int inv_mpu_probe(struct spi_device *spi)
 
 	regmap = devm_regmap_init_spi(spi, &inv_mpu_regmap_config);
 	if (IS_ERR(regmap)) {
-		dev_err(&spi->dev, "Failed to register spi regmap %d\n",
-			(int)PTR_ERR(regmap));
+		dev_err(&spi->dev, "Failed to register spi regmap: %pe\n",
+			regmap);
 		return PTR_ERR(regmap);
 	}