ASoC: wcd9335: remove redundant use of ret variable

All these functions declares and initializes variable ret with
'0' and without modifying 'ret' variable, it is returned.

This patch removes this redundancy and returns '0' directly.

Signed-off-by: Saiyam Doshi <saiyamdoshi.in@gmail.com>
Link: https://lore.kernel.org/r/20190909174541.GA22718@SD


Signed-off-by: Mark Brown <broonie@kernel.org>