Bluetooth: Simplify hci_conn_params->action list usage

Since params->action is used for both the pend_le_conns and
pend_le_reports lists we can simplify the adding and deleting of the
lists considerably. For example, when deleting entries in most
situations we no-longer need to check the auto_connect value but can
directly proceed with calling list_del_init on param->action (which is
safe even if the entry is not part of any list).

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>