platform/x86: intel-wmi-thunderbolt: Silence error cases

These were raised by Lukas Wunner as potential DOS attacks against
the system log by passing bad data to sysfs.

Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>