FIX ofp_test_arp test after ODP 1.5 update change in ad9570b.
FIX ofp_test_arp test after ODP 1.5 update change in ad9570b.

Change from b0e4d68 was not integrated in ad9570b.

Signed-off-by: Sorin Vultureanu <8013ba55f8675034bc2ab0d6c3a1c9650437ca36@enea.com>
Reviewed-and-tested-by: José Pekkarinen <d7cb8761fb0e75b1a78c2fda4f1daed76cd46cfe@nokia.com>

OpenFastPath/ofp,OpenFastPath/ofp,OpenFastPath/ofp,TolikH/ofp,OpenFastPath/ofp,TolikH/ofp,TolikH/ofp