power: supply: bq24190: Fix use after free bug in bq24190_remove due to race condition

In bq24190_probe, &bdi->input_current_limit_work is bound
with bq24190_input_current_limit_work. When external power
changed, it will call bq24190_charger_external_power_changed
 to start the work.

If we remove the module which will call bq24190_remove to make
cleanup, there may be a unfinished work. The possible
sequence is as follows:

CPU0                  CPUc1

                    |bq24190_input_current_limit_work
bq24190_remove      |
power_supply_unregister  |
device_unregister   |
power_supply_dev_release|
kfree(psy)          |
                    |
                    | power_supply_get_property_from_supplier
                    |   //use

Fix it by finishing the work before cleanup in the bq24190_remove

Fixes: 97774672573a ("power_supply: Initialize changed_work before calling device_add")
Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
