When devm_kcalloc() fails, we should execute device_unregister()
to unregister edev->dev from system.
Fixes: 046050f6e623e ("extcon: Update the prototype of extcon_register_notifier() with enum extcon") Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>