Bluetooth: use the proper scan params when conn is pending

When an LE connection is requested and an RPA update is needed via
hci_connect_le_scan, the default scanning parameters are used rather
than the connect parameters.  This leads to significant delays in the
connection establishment process when using lower duty cycle scanning
parameters.

The patch simply looks at the pended connection list when trying to
determine which scanning parameters should be used.

Before:
< HCI Command: LE Set Extended Scan Parameters (0x08|0x0041) plen 8
                            #378 [hci0] 1659.247156
        Own address type: Public (0x00)
        Filter policy: Ignore not in white list (0x01)
        PHYs: 0x01
        Entry 0: LE 1M
          Type: Passive (0x00)
          Interval: 367.500 msec (0x024c)
          Window: 37.500 msec (0x003c)

After:
< HCI Command: LE Set Extended Scan Parameters (0x08|0x0041) plen 8
                               #39 [hci0] 7.422109
        Own address type: Public (0x00)
        Filter policy: Ignore not in white list (0x01)
        PHYs: 0x01
        Entry 0: LE 1M
          Type: Passive (0x00)
          Interval: 60.000 msec (0x0060)
          Window: 60.000 msec (0x0060)

Signed-off-by: Alain Michaud <alainm@chromium.org>
Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Reviewed-by: Yu Liu <yudiliu@google.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>