The WTAP_ENCAP_ETHERNET dissector needs to be passed a struct eth_phdr.

We now require that.  Make it so.

Bug: 12440
Change-Id: Iffee520976b013800699bde3c6092a3e86be0d76
Reviewed-on: https://code.wireshark.org/review/15424
Reviewed-by: Guy Harris <guy@alum.mit.edu>
static void rpcap_frame_end (void)
{
  info_added = FALSE;
}

static void rpcap_frame_end (void)
{
  info_added = FALSE;
}
