char: xillybus: Simplify 'xillybus_init_endpoint()'

Ths first argument of 'xillybus_init_endpoint()' is now useless.
Remove it.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/ba687c1eff5dc8f21422323f57164d06f25d4169.1630083668.git.christophe.jaillet@wanadoo.fr


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