Merge pull request #3006 from pacovn/static_analysis__shadow_variables1

bgpd isisd ospf6d ospfd: variable shadowing fixes

diff --cc bgpd/bgp_attr.c
Simple merge

diff --cc ospfd/ospf_nsm.c
Simple merge

diff --cc ospfd/ospf_packet.c
Simple merge

diff --cc ospfd/ospf_zebra.c
Simple merge

diff --cc ospfd/ospfd.c
Simple merge