packet-sscop.c: various:

- Add/use extended value-string;
- Add editor-modelines and adjust whitespace as needed.

Change-Id: I5e03d6bcaeb2f4beee37ad4778a87657ae82128d
Reviewed-on: https://code.wireshark.org/review/4388
Reviewed-by: Bill Meier <wmeier@newsguy.com>