usb: typec: displayport: Reduce noise from the driver

It's not an error if the mode can't be entered because
another mode is already active, so no longer printing an
error message if that happens.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20200928133324.48841-1-heikki.krogerus@linux.intel.com


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