hwmon: (ibmaem) don't call platform_device_del() if platform_device_add() fails

If platform_device_add() fails, it no need to call platform_device_del(), split
platform_device_unregister() into platform_device_del/put(), so platform_device_put()
can be called separately.

Fixes: 8808a793 ("ibmaem: new driver for power/energy/temp meters in IBM System X hardware")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20220701074153.4021556-1-yangyingliang@huawei.com


Signed-off-by: Guenter Roeck <linux@roeck-us.net>