Fix resource reclaim in below cases:

1. acerhdf_register_platform() does not properly handle
   platform_device_alloc() failure and platform_device_add() failure This
   patch adds error handing for acerhdf_register_platform().

2. acerhdf_register_platform() return err with acerhdf_dev == NULL.
   as a result, acerhdf_unregister_platform() does not do resource reclaim
   in acerhdf_init() error path.  This patch adds error handing for
   acerhdf_register_platform(), thus correct the error handing path in
   acerhdf_init().  goto out_err instead of err_unreg if
   acerhdf_register_platform() fail.

3. platform_device_del() should only used in error handling.  Current
   implementation missed a platform_device_put() in acerhdf_exit.  This
   patch fixes it by using platform_device_unregister() instead of
   platform_device_del() in acerhdf_unregister_platform.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Peter Feuerer <peter@piie.net>
Cc: Matthew Garrett <mjg@redhat.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Matthew Garrett <mjg@redhat.com>