Improved tracing for the IP[46] not-enabled case.

Improved tracing for the IP[46] not-enabled case.

now we get
00:00:03:665501: pg-input
 ...
00:00:03:665681: ethernet-input
 ...
00:00:03:665691: ip6-input
  UDP: 2001::1 -> ffef::1
    tos 0x00, flow label 0x0, hop limit 64, payload length 108
  UDP: 1234 -> 1234
    length 108, checksum 0x7b25
00:00:03:665695: ip6-not-enabled
    UDP: 2001::1 -> ffef::1
      tos 0x00, flow label 0x0, hop limit 64, payload length 108
    UDP: 1234 -> 1234
      length 108, checksum 0x7b25
00:00:03:665706: error-drop
  ethernet-input: no error

Same goes for IPv4

Change-Id: Ia360df39b43281d3a0aa1b686f04b73cfa37c546
Signed-off-by: Neale Ranns <nranns@cisco.com>