Revision 356456

MFC r355070:

  Allow kernel to compile without BPF.

  r297816 added some bpf magic for VIMAGE unconditionally which no longer
  allows kernels to compile without bpf (but with other networking).
  Add the missing ifdef checks and allow a kernel to compile without bpf
  again.

  PR:		242136
  Reported by:	dave mischler.com
  MFC after:	2 weeks