can: kvaser_usb: Fix possible completions during init_completion

can: kvaser_usb: Fix possible completions during init_completion

kvaser_usb uses completions to signal when a response event is received
for outgoing commands.

However, it uses init_completion() to reinitialize the start_comp and
stop_comp completions before sending the start/stop commands.

In case the device sends the corresponding response just before the
actual command is sent, complete() may be called concurrently with
init_completion() which is not safe.

This might be triggerable even with a properly functioning device by
stopping the interface (CMD_STOP_CHIP) just after it goes bus-off (which
also causes the driver to send CMD_STOP_CHIP when restart-ms is off),
but that was not tested.

Fix the issue by using reinit_completion() instead.

Fixes: d9f21bf91c45 ("can: kvaser_usb: Add support for Kvaser CAN/USB devices")
Tested-by: Jimmy Assarsson <extja@kvaser.com>
Signed-off-by: Anssi Hannula <anssi.hannula@bitwise.fi>
Signed-off-by: Jimmy Assarsson <extja@kvaser.com>
Link: https://lore.kernel.org/all/20221010185237.319219-2-extja@kvaser.com
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>