drivers: iio: imu: Moved mutex lock after return function

The mutex lock will be in dead lock condition if early buffer flag
is true , to avoid that moved mutex lock after return function.

Change-Id: Ie043091533cf670494418467af5d3770e4f2471d
Signed-off-by: Puneet Yatnal <puneet@codeaurora.org>
4 files changed