Improve compilation when not INET and INET6 are both defined.
Improve compilation when not INET and INET6 are both defined.

sctplab/usrsctp,sctplab/usrsctp,saghul/usrsctp,weinrank/usrsctp,CoolmanCZ/usrsctp,sctplab/usrsctp,bebo/usrsctp,faithfracture/usrsctp,CoolmanCZ/usrsctp,JlnWntr/usrsctp,CoolmanCZ/usrsctp,JlnWntr/usrsctp,liamstask/usrsctp,liamstask/usrsctp,CoolmanCZ/usrsctp,sukinull/usrsctp,sukinull/usrsctp,ossy-szeged/usrsctp,weinrank/usrsctp,faithfracture/usrsctp,ossy-szeged/usrsctp,bebo/usrsctp,faithfracture/usrsctp,saghul/usrsctp,JlnWntr/usrsctp,weinrank/usrsctp