platform/x86: thinkpad_acpi: Correct minor typo

Signed-off-by: Esteve Varela Colominas <esteve.varela@gmail.com>
Link: https://lore.kernel.org/r/20210321183512.14551-1-esteve.varela@gmail.com


Signed-off-by: Hans de Goede <hdegoede@redhat.com>