Bluetooth: Fix advertising handle is set to 0

This patch fix the advertising handle is set to 0 regardless of actual
instance value. The affected commands are LE Set Advertising Set Random
Address, LE Set Extended Advertising Data, and LE Set Extended Scan
Response Data commands.

Signed-off-by: Tedd Ho-Jeong An <tedd.an@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>