Welcome to LQ.
I think the 'waf' you are supposed to use is :
I.e. $ cd ns-allinone-3.21/ns-3.21/ && ./waf --run qos-test
Should be fairly easy to sort out, as the above is the only waf in ns-3.21 :
$ cd ns-allinone-3.21/ns-3.21/ && find . -name waf
Ns3, "Getting Started" :
P.S. : The ns3 Forum is here ....