Bluetooth: Fix append max 11 bytes of name to scan rsp data

Append maximum of 10 + 1 bytes of name to scan response data.
Complete name is appended only if exists and is <= 10 characters.
Else append short name if exists or shorten complete name if not.
This makes sure name is consistent across multiple advertising
instances.

Signed-off-by: Michał Narajowski <michal.narajowski@codecoup.pl>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>