can: c_can: disable one shot mode until driver is fixed

This patch disables the one shot mode, until the driver has been fixed and
tested to support it.

> I'm quite sure I've seen a situation where msg_obj 17 "seemed" to be
> pending, while msg_obj 18 and 19 already have been transmitted. But
> in that case, I enabled ONESHOT for the can interface, which enables
> the DA mode (automatic retransmission is disabled).

Reported-by: Jan Altenberg <jan@linutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Kurt Van Dijck <kurt.van.dijck@eia.be>
Cc: Bhupesh Sharma <bhupesh.sharma@st.com>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>