Since bpf_allocbufs() uses malloc() with M_WAITOK, don't check return values for NULL or return an error state.  Assert that all three bpf buffer pointers are NULL before starting.
Since bpf_allocbufs() uses malloc() with M_WAITOK, don't check return
values for NULL or return an error state.  Assert that all three bpf
buffer pointers are NULL before starting.

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