USB: allow some usb functions to take a const pointer.

USB: allow some usb functions to take a const pointer.

The functions to_usb_interface(), to_usb_device, and
interface_to_usbdev() sometimes would like to take a const * and return
a const * back.  As we are doing pointer math, a call to container_of()
loses the const-ness of a pointer, so use a _Generic() macro to pick the
proper inline function to call instead.

Link: https://lore.kernel.org/r/20221016104155.1260201-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>