source-nfq: fix display of next queue

Suricata was displaying an invalid queue number as the value is
shift at the moment of its assignement.

PR builds:
- PR build: https://buildbot.openinfosecfoundation.org/builders/regit/builds/11
- PR pcaps: https://buildbot.openinfosecfoundation.org/builders/regit-pcap/builds/9