firmware: vpd: Fix platform driver and device registration/unregistration

firmware: vpd: Fix platform driver and device registration/unregistration

commit 0631fb8b027f5968c2f5031f0b3ff7be3e4bebcc upstream.

The driver exit function needs to unregister both platform device and
driver. Also, during registration, register driver first and perform
error checks.

Fixes: 049a59db34eb ("firmware: Google VPD sysfs driver")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>