ALSA: hda/ca0132: Remove double parentheses

The extra pairs of parantheses are not needed and causes clang to
generate warnings like this:

sound/pci/hda/patch_ca0132.c:1171:14: error: equality comparison with extraneous parentheses [-Werror,-Wparentheses-equality]
        if ((buffer == NULL))
             ~~~~~~~^~~~~~~
sound/pci/hda/patch_ca0132.c:1171:14: note: remove extraneous parentheses around the comparison to silence this warning
        if ((buffer == NULL))
            ~       ^      ~
sound/pci/hda/patch_ca0132.c:1171:14: note: use '=' to turn this equality comparison into an assignment
        if ((buffer == NULL))

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>