Merge pull request #10076 from idryzhov/if-is-loopback-or-vrf

*: unify if_is_loopback/if_is_loopback_or_vrf

diff --cc isisd/isis_circuit.c
Simple merge

diff --cc lib/if.c
Simple merge

diff --cc lib/if.h
Simple merge

diff --cc pimd/pim_vxlan.c
Simple merge