Remove this unneeded mutex. Indeed it was used to serialize access to
the hardware, but this is already done by the i2c-core layer, see
'bus_lock' mutex used by i2c_transfer().
Signed-off-by: NFrancis Moreau <francis.moro@gmail.com>
Acked-by: NBryan Wu <bryan.wu@analog.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>