Fix for generating printf args in c backend.
Fix for generating printf args in c backend.

dougkwan/Halide,tdenniston/Halide,kgnk/Halide,damienfir/Halide,kgnk/Halide,adasworks/Halide,rodrigob/Halide,kenkuang1213/Halide,ronen/Halide,kenkuang1213/Halide,dougkwan/Halide,smxlong/Halide,myrtleTree33/Halide,ronen/Halide,aam/Halide,gchauras/Halide,rodrigob/Halide,lglucin/Halide,dougkwan/Halide,mikeseven/Halide,mikeseven/Halide,lglucin/Halide,adasworks/Halide,gchauras/Halide,lglucin/Halide,ronen/Halide,delcypher/Halide,psuriana/Halide,tdenniston/Halide,tdenniston/Halide,mikeseven/Halide,delcypher/Halide,damienfir/Halide,gchauras/Halide,psuriana/Halide,kgnk/Halide,kenkuang1213/Halide,kgnk/Halide,rodrigob/Halide,myrtleTree33/Halide,kenkuang1213/Halide,kenkuang1213/Halide,gchauras/Halide,ayanazmat/Halide,delcypher/Halide,smxlong/Halide,jiawen/Halide,mcanthony/Halide,myrtleTree33/Halide,jiawen/Halide,ayanazmat/Halide,psuriana/Halide,dan-tull/Halide,jiawen/Halide,dougkwan/Halide,myrtleTree33/Halide,adasworks/Halide,dan-tull/Halide,ayanazmat/Halide,adasworks/Halide,mikeseven/Halide,fengzhyuan/Halide,psuriana/Halide,psuriana/Halide,delcypher/Halide,ronen/Halide,fengzhyuan/Halide,gchauras/Halide,aam/Halide,ayanazmat/Halide,damienfir/Halide,jiawen/Halide,dan-tull/Halide,lglucin/Halide,kgnk/Halide,psuriana/Halide,dan-tull/Halide,adasworks/Halide,kgnk/Halide,damienfir/Halide,smxlong/Halide,mcanthony/Halide,mcanthony/Halide,smxlong/Halide,myrtleTree33/Halide,mcanthony/Halide,rodrigob/Halide,mcanthony/Halide,dougkwan/Halide,gchauras/Halide,lglucin/Halide,tdenniston/Halide,kenkuang1213/Halide,delcypher/Halide,jiawen/Halide,aam/Halide,jiawen/Halide,smxlong/Halide,dougkwan/Halide,rodrigob/Halide,mcanthony/Halide,ayanazmat/Halide,fengzhyuan/Halide,smxlong/Halide,ayanazmat/Halide,mikeseven/Halide,fengzhyuan/Halide,kgnk/Halide,fengzhyuan/Halide,dougkwan/Halide,myrtleTree33/Halide,damienfir/Halide,delcypher/Halide,smxlong/Halide,rodrigob/Halide,kgnk/Halide,damienfir/Halide,ayanazmat/Halide,dan-tull/Halide,tdenniston/Halide,aam/Halide,dougkwan/Halide,smxlong/Halide,tdenniston/Halide,ayanazmat/Halide,ronen/Halide,tdenniston/Halide,mcanthony/Halide,mcanthony/Halide,kenkuang1213/Halide,myrtleTree33/Halide,ronen/Halide,damienfir/Halide,kenkuang1213/Halide,myrtleTree33/Halide,rodrigob/Halide,aam/Halide,damienfir/Halide,fengzhyuan/Halide,dan-tull/Halide,dan-tull/Halide,fengzhyuan/Halide,adasworks/Halide,dan-tull/Halide,psuriana/Halide,adasworks/Halide,lglucin/Halide,fengzhyuan/Halide,ronen/Halide,adasworks/Halide,rodrigob/Halide,tdenniston/Halide,ronen/Halide,aam/Halide,delcypher/Halide,aam/Halide,delcypher/Halide,jiawen/Halide,lglucin/Halide