usb: gadget: f_uac1: replace scnprintf() with sysfs_emit()

Documentation/filesystems/sysfs.rst mentions that show() should only
use sysfs_emit() or sysfs_emit_at() when formating the value to be
returned to user space. So replace scnprintf() with sysfs_emit().

Signed-off-by: Sumanth Gavini <sumanth.gavini@yahoo.com>
Link: https://lore.kernel.org/r/20250718175037.299710-1-sumanth.gavini@yahoo.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>