gpio: exar: add a check for the return value of ida_simple_get fails

ida_simple_get may fail and return a negative error number.
The fix checks its return value; if it fails, go to err_destroy.

Cc: <stable@vger.kernel.org>
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>