Input: uinput - fix typo in function name documentation

Fix non-existing constant in documentation.

Signed-off-by: Pavel Machek (CIP) <pavel@denx.de>
Link: https://lore.kernel.org/r/20200724084025.GB31930@amd


Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>