firmware: vpd: Destroy vpd sections in remove function

vpd sections are initialized during probe and thus should be destroyed
in the remove function.

Fixes: 049a59db ("firmware: Google VPD sysfs driver")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>