ALSA: hda/cirrus: Cleanup patch_cirrus.c code.

Minor changes, clean up code, remove unnecessary
initialization of variables, reduced number of
warnings from ./scripts/checkpatch.pl from 19 to 0

Tested on DELL Inspiron-3505, DELL Inspiron-3501, DELL Inspiron-3500
Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com>
Signed-off-by: Vitaly Rodionov <vitalyr@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20210315190716.47686-3-vitalyr@opensource.cirrus.comSigned-off-by: Takashi Iwai <tiwai@suse.de>