extcon: max77843: Return error code of extcon_dev_allocate()

devm_extcon_dev_allocate() can fail of multiple reasons.  The call
returns proper error code on failure so pass it instead of fixed ENOMEM.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>