of_json: Fix regression with actions
of_json: Fix regression with actions

While cleaning up libopenflow actions in 4378bea837, I changed
an "internal API" which broke of_json.  Fixed.

Thanks to faizul bari for pointing it out.

adusia/pox,carlye566/IoT-POX,chenyuntc/pox,pthien92/sdn,xAKLx/pox,PrincetonUniversity/pox,noxrepo/pox,chenyuntc/pox,noxrepo/pox,pthien92/sdn,jacobq/csci5221-viro-project,waltznetworks/pox,adusia/pox,diogommartins/pox,kpengboy/pox-exercise,MurphyMc/pox,pthien92/sdn,kulawczukmarcin/mypox,denovogroup/pox,xAKLx/pox,denovogroup/pox,PrincetonUniversity/pox,denovogroup/pox,PrincetonUniversity/pox,waltznetworks/pox,waltznetworks/pox,xAKLx/pox,kpengboy/pox-exercise,pthien92/sdn,carlye566/IoT-POX,kpengboy/pox-exercise,VamsikrishnaNallabothu/pox,waltznetworks/pox,carlye566/IoT-POX,adusia/pox,jacobq/csci5221-viro-project,kulawczukmarcin/mypox,noxrepo/pox,noxrepo/pox,MurphyMc/pox,kavitshah8/SDNDeveloper,carlye566/IoT-POX,waltznetworks/pox,denovogroup/pox,kavitshah8/SDNDeveloper,diogommartins/pox,denovogroup/pox,jacobq/csci5221-viro-project,xAKLx/pox,VamsikrishnaNallabothu/pox,PrincetonUniversity/pox,VamsikrishnaNallabothu/pox,adusia/pox,VamsikrishnaNallabothu/pox,PrincetonUniversity/pox,diogommartins/pox,MurphyMc/pox,VamsikrishnaNallabothu/pox,pthien92/sdn,kpengboy/pox-exercise,diogommartins/pox,kulawczukmarcin/mypox,diogommartins/pox,kavitshah8/SDNDeveloper,andiwundsam/_of_normalize,MurphyMc/pox,andiwundsam/_of_normalize,chenyuntc/pox,kulawczukmarcin/mypox,xAKLx/pox,chenyuntc/pox,andiwundsam/_of_normalize,MurphyMc/pox,kulawczukmarcin/mypox,jacobq/csci5221-viro-project,jacobq/csci5221-viro-project,kavitshah8/SDNDeveloper,andiwundsam/_of_normalize,chenyuntc/pox,kpengboy/pox-exercise,carlye566/IoT-POX,adusia/pox