ASoC: wm8994: missing break in wm8994_get_fll_config()

Smatch complains that:

	sound/soc/codecs/wm8994.c:2087 wm8994_get_fll_config()
		warn: missing break? reassigning 'fll->k'

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>