gpio: aggregator: Fix off by one in gpiochip_fwd_desc_add()

gpio: aggregator: Fix off by one in gpiochip_fwd_desc_add()

The "> chip->ngpio" comparison here needs to be ">= chip->ngpio",
otherwise it leads to an out of bounds access.  The fwd->valid_mask
bitmap only has chip->ngpio bits and the fwd->descs[] array has that
same number of elements.  These values are set in
devm_gpiochip_fwd_alloc().

Fixes: c44ce91b8ada ("gpio: aggregator: refactor the code to add GPIO desc in the forwarder")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/aJwk0yBSCccGCjX3@stanley.mountain
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>