ALSA: usb-audio: Refactor ignore_ctl_error checks

Introduce an internal helper macro for avoiding many open codes.

The only slight behavior change is in a couple of get ballcks where
the value is reset at error no matter whether ignore_ctl_error is set
or not.  Actually this is even safer than before.

Signed-off-by: Takashi Iwai <tiwai@suse.de>