extcon: intel-cht-wc: Ignore failure to detect charger-type on host mode exit

When we leave host-mode because the id-pin is no longer connected to
ground, the 5v boost converter is normally still on, so we will see
Vbus, but it is not from a charger (normally) so the charger-type
detection will fail.

This commit silences the cht_wc_extcon_get_charger() false-positive
errors when we're leaving host mode.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>