pinctrl: sunxi: Testing the wrong variable

Smatch complains that we dereference "map" before testing it for NULL
which is true.  We should be testing "*map" instead.  Also on the error
path, we should free *map and set it to NULL.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>