No attempt has been made to document any of the demoted functions here.

Fixes the following W=1 kernel build warning(s):

 drivers/usb/gadget/function/u_uac1_legacy.c:30: warning: Function parameter or member 'i' not described in 'snd_interval_refine_set'
 drivers/usb/gadget/function/u_uac1_legacy.c:30: warning: Function parameter or member 'val' not described in 'snd_interval_refine_set'
 drivers/usb/gadget/function/u_uac1_legacy.c:93: warning: Function parameter or member 'snd' not described in 'playback_default_hw_params'
 drivers/usb/gadget/function/u_uac1_legacy.c:153: warning: Function parameter or member 'card' not described in 'u_audio_playback'
 drivers/usb/gadget/function/u_uac1_legacy.c:153: warning: Function parameter or member 'buf' not described in 'u_audio_playback'
 drivers/usb/gadget/function/u_uac1_legacy.c:153: warning: Function parameter or member 'count' not described in 'u_audio_playback'
 drivers/usb/gadget/function/u_uac1_legacy.c:197: warning: Function parameter or member 'card' not described in 'gaudio_open_snd_dev'
 drivers/usb/gadget/function/u_uac1_legacy.c:257: warning: Function parameter or member 'gau' not described in 'gaudio_close_snd_dev'
 drivers/usb/gadget/function/u_uac1_legacy.c:286: warning: Function parameter or member 'card' not described in 'gaudio_setup'
 drivers/usb/gadget/function/u_uac1_legacy.c:303: warning: Function parameter or member 'the_card' not described in 'gaudio_cleanup'

Cc: Felipe Balbi <balbi@kernel.org>
Cc: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20200706133341.476881-20-lee.jones@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>