The identifier of the port in the peer node connected
to this port.
If the peer node is a channel, as described
by the instance of fcIfRNIDInfoUnitType, then
fcIfRNIDInfoPortId will be the CHPID (Channel
Path Identifier) of the channel path that
contains the port in the peer node connected to this
port.
If the peer node is controlUnit, then
fcIfRNIDInfoPortId will be 0.
If the peer node is fabric, then
fcIfRNIDInfoPortId will be port address of the port in
peer node connected to this port.