ASoC: cs35l35: Add local variable for dev in probe

Tidy up the code a little by adding a local variable for i2c_client->dev
rather than referring to it explicitly everytime.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Acked-by: Brian Austin <brian.austin@cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>