test: arp: Don't call ofp_init_local() twice in the main thread
test: arp: Don't call ofp_init_local() twice in the main thread

ofp_init_local() is called in suite init, don't call it again in
test_arp().

Signed-off-by: Jere Leppänen <14957520de8d9815e0c353a07fe23c737f0171e9@nokia.com>
Reviewed-by: Tuomas Taipale <d030d77d5671b12fc82a6b4397d4c4cdb188b540@nokia.com>

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