iwlwifi: fix name of function in comment (_rx_card_state_notif)

iwl_rx_card_state_notif is named iwl3945_rx_card_state_notif and
iwl4965_rx_card_state_notif in the two iwlwifi drivers.

Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>