Logcat: Remove commented code

"g_strlcpy" guarante that "dest" to be null-terminated.

Also cosmetic change from file_subtype to encap.

Change-Id: If188a08cf34dd9def4203404962571c273740636
Reviewed-on: https://code.wireshark.org/review/2718
Reviewed-by: Michal Labedzki <michal.labedzki@tieto.com>