update olsr_spf_relax to call olsr_spf_decrease_key
update olsr_spf_relax to call olsr_spf_decrease_key

now the process to update the new pathcost is on olsr_spf_decrease_key

diogomg/olsrd-binary-heap,diogomg/olsrd-binary-heap,diogomg/olsrd-binary-heap,diogomg/olsrd-binary-heap,diogomg/olsrd-binary-heap,diogomg/olsrd-binary-heap,diogomg/olsrd-binary-heap