gpiolib: Join one line back for better readability

One line in gpiolib_dbg_show() still fits 80 characters, so,
join it to be like that in order to increase readability.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>