wccp: use pinfo-scope memory for addresses

They may be accessed during the print phase, at which point packet-scope memory
has already been freed.

Bug: 10720
Change-Id: Ia2b160fd9de4ccaa3a4b8d9cb70fb9b32d4e08a0
Reviewed-on: https://code.wireshark.org/review/5496
Reviewed-by: Evan Huus <eapache@gmail.com>
(cherry picked from commit e843c6797db98bfceab382d5d7e76727e1014f5e)
Conflicts:
	epan/dissectors/packet-wccp.c
Reviewed-on: https://code.wireshark.org/review/6057
Reviewed-by: Pascal Quantin <pascal.quantin@gmail.com>