iio: gyro: mpu3050: Fix error handling in mpu3050_trigger_handler

There is one regmap_bulk_read() call in mpu3050_trigger_handler
that we have caught its return value bug lack further handling.
Check and terminate the execution flow just like the other three
regmap_bulk_read() calls in this function.

Fixes: 3904b28e

 ("iio: gyro: Add driver for the MPU-3050 gyroscope")
Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20210301080421.13436-1-dinghao.liu@zju.edu.cn
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>