Mfp4 CH=177256:
Mfp4 CH=177256:

  Catch a set vnet upon return to user space. This usually
  means return paths with CURVNET_RESTORE() missing.

  If VNET_DEBUG is turned on we can even tell the function
  that did the CURVNET_SET() which is really helpful; else
  we print "N/A".

  Sponsored by: The FreeBSD Foundation
  Sponsored by: CK Software GmbH
  Reviewed by:  jhb

MFC after:	11 days

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