Bluetooth: Count pending LE connection attempts

To avoid traversing the hci_conn list every time we get an advertising
report, we keep a counter of pending LE connection attempts (connections
in HCI_CONN_LE_SCAN state). This way, we only traverse the list if the
counter is greater from zero.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
WIP: Bluetooth: Remove status handling in hci_cs_le_create_conn

This patch removes the status error handling in hci_cs_le_create_conn
since this is alreay handled in le_conn_initiate_complete callback.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Bluetooth: Remove unused functions

This patch removes the unused functions hci_le_create_connection and
hci_le_create_connection_cancel.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Blutooth: Make hci_conn_fail_pending non-static

This patch makes hci_conn_fail_pending helper non-local so it can be
used in hci_event.c.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
WIP: Bluetooth: Initial support for multiple LE connections

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Bluetooth: Add passive scanning trigger

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Bluetooth: Remove BT_CONNECT check in hci_connect_le

Since the we supported only on LE connection attempt at a time, we
had to check if we already had one connection attempt running.
However, now we support multiple LE connection attempts so we can
safely remove this check in hci_connect_le function.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Bluetooth: Don't set chan_timer for ATT fixed channel

According to Core spec (see Vol 3, Part A, 6.2.1), the channel timer
used to terminate the channel when the remote endpoint is unreponsive
to signaling requests. Since there is no signaling requests in LE ATT
fixed channel, there is no need we setup this timer.

As a side effect, LE connection attempts won't be aborted by the
channel timer anymore. Therefore, SOCK_NONBLOCK LE L2CAP sockets will
be ready (will receive POLLOUT event) when the LE connection is
established.

This patch modifies l2cap_chan_connect function so it doesn't set
the timer if the cid is L2CAP_CID_LE_DATA.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>