Bluetooth: Fix updating background scan for LE connect complete

When we get an LE connection complete event we should restart background
scanning if there are any devices needing it. So far the code was only
making the decision based on whether the completed connection had any
stored parameters or not. This patch ensures that we trigger background
scanning always when necessary.

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