pinctrl: Print the correct information in debugfs pinconf-state file

A bad copy&paste resulted in the debugfs pinconf-state file printing the
pin name instead of the state name. Fix it.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>