Bluetooth: Simplify UUID16 list generation for EIR

There's no need to use two separate loops to generate a UUID list for
the EIR data. This patch merges the two loops previously used for the
16-bit UUID list generation into a single loop, thus simplifying the
code a great deal.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>