Bluetooth: Fix remove_passive_scan_trigger

If device discovery is running, we should not disable the scanning
in remove_passive_scan_trigger. Otherwise, we may brake the discovery
state machine.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Bluetooth: Temporarily disable passive scanning on Discovery

If the user send a mgmt start discovery command while the passive
passive scanning is running, we should temporarily disable the
passive scanning. Once the discovery finishes, we enable the passive
scanning again.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Bluetooth: Stop discovery if pending connection

In case a LE device we want to connect to is found during the device
discovery procedure, we should initiate the connection. Since some LE
controllers don't support scanning and initiating state combination,
the scanning will be disabled, therefore we should set the discovery
state to DISCOVERY_STOPPED.

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