Fix a bug where TAILQ_FIRST(&V_ifnet) was accessed without holding the proper lock.
Fix a bug where TAILQ_FIRST(&V_ifnet) was accessed without holding the
proper lock.

Reviewed by:	bz
MFC after:	1 week

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase