MFC r271917 by hrs:   Virtualize interface cloner for gif(4).  This fixes a panic when destroying   a vnet jail which has a gif(4) interface.
MFC r271917 by hrs:
  Virtualize interface cloner for gif(4).  This fixes a panic when destroying
  a vnet jail which has a gif(4) interface.

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