CVE-2021-47437

In the Linux kernel, the following vulnerability has been resolved:

iio: adis16475: fix deadlock on frequency set

With commit 39c024b51b560 ("iio: adis16475: improve sync scale mode handling"), two deadlocks were introduced:

1. The call to 'adis_write_reg_16()' was not changed to it's unlocked version.
2. The lock was not being released on the success path of the function.

This change fixes both these issues.