Currently when the uncore_write() returns error, it is silently
ignored. Return error to user space when uncore_write() fails.

Fixes: 49a474c7 ("platform/x86: Add support for Uncore frequency control")
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Reviewed-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Wendy Wang <wendy.wang@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230418153230.679094-1-srinivas.pandruvada@linux.intel.com
Cc: stable@vger.kernel.org
Signed-off-by: Hans de Goede <hdegoede@redhat.com>