power: supply: bq24190_charger: Fix runtime PM imbalance on error

pm_runtime_get_sync() increments the runtime PM usage counter even
it returns an error code. Thus a pairing decrement is needed on
the error handling path to keep the counter balanced.

Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>