x86, intel_cacheinfo: fix use-after-free cache_kobject

This avoids calling kobject_uevent() with cache_kobject that has
already been deallocated in an error path.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>