In atmel_conf_pin_config_dbg_show(), checking atmel_pioctrl->pins[pin_id]
against being NULL doesn't make any sense as it gets derefenced first and
the driver's probe() method immediately returns -ENOMEM when devm_kzalloc()
returns NULL for any atmel_pioctrl->pins[] element anyway, thus failing to
register the device...
Found by Linux Verification Center (linuxtesting.org) with the Svace static
analysis tool.