Fix typo - ac defined are prefixed with FOLLY_
Fix typo - ac defined are prefixed with FOLLY_

Summary: Got this ifdef wrong in my last change here.

Reviewed By: @paulbiss

Differential Revision: D2213708

lifei/folly,floxard/folly,constantine001/folly,tomhughes/folly,floxard/folly,fw1121/folly,PPC64/folly,SammyK/folly,sonnyhu/folly,gaoyingie/folly,tempbottle/folly,clearlylin/folly,PPC64/folly,rklabs/folly,brunomorishita/folly,shaobz/folly,guker/folly,constantine001/folly,renyinew/folly,shaobz/folly,shaobz/folly,yangjin-unique/folly,theiver9827/folly,reddit/folly,clearlylin/folly,cole14/folly,clearlylin/folly,alexst07/folly,sakishum/folly,theiver9827/folly,Hincoin/folly,xzmagic/folly,stonegithubs/folly,PoisonBOx/folly,shaobz/folly,PoisonBOx/folly,PoisonBOx/folly,lifei/folly,shaobz/folly,KSreeHarsha/folly,guker/folly,mqeizi/folly,fw1121/folly,tomhughes/folly,wildinto/folly,alexst07/folly,lifei/folly,facebook/folly,leolujuyi/folly,Hincoin/folly,chjp2046/folly,constantine001/folly,raphaelamorim/folly,Hincoin/folly,bowlofstew/folly,juniway/folly,colemancda/folly,chjp2046/folly,Eagle-X/folly,upsoft/folly,fw1121/folly,Orvid/folly,constantine001/folly,alexst07/folly,SeanRBurton/folly,sakishum/folly,upsoft/folly,SammyK/folly,arg0/folly,arg0/folly,hongliangzhao/folly,sakishum/folly,zhiweicai/folly,PoisonBOx/folly,facebook/folly,PPC64/folly,gaoyingie/folly,reddit/folly,KSreeHarsha/folly,charsyam/folly,mqeizi/folly,bobegir/folly,hongliangzhao/folly,doctaweeks/folly,PPC64/folly,SammyK/folly,bobegir/folly,SammyK/folly,leolujuyi/folly,arg0/folly,KSreeHarsha/folly,lifei/folly,renyinew/folly,upsoft/folly,bikong2/folly,SeanRBurton/folly,brunomorishita/folly,cole14/folly,raphaelamorim/folly,cole14/folly,leolujuyi/folly,bobegir/folly,kernelim/folly,kernelim/folly,SeanRBurton/folly,juniway/folly,arg0/folly,kernelim/folly,renyinew/folly,xzmagic/folly,gavioto/folly,tempbottle/folly,fw1121/folly,kernelim/folly,PPC64/folly,charsyam/folly,tomhughes/folly,rklabs/folly,nickhen/folly,charsyam/folly,bobegir/folly,juniway/folly,rklabs/folly,brunomorishita/folly,xzmagic/folly,lifei/folly,alexst07/folly,stonegithubs/folly,colemancda/folly,Orvid/folly,zhiweicai/folly,juniway/folly,wildinto/folly,bowlofstew/folly,chjp2046/folly,KSreeHarsha/folly,CJstar/folly,raphaelamorim/folly,Eagle-X/folly,gaoyingie/folly,leolujuyi/folly,colemancda/folly,CJstar/folly,wildinto/folly,gaoyingie/folly,doctaweeks/folly,zhiweicai/folly,stonegithubs/folly,reddit/folly,brunomorishita/folly,yangjin-unique/folly,reddit/folly,stonegithubs/folly,bowlofstew/folly,bowlofstew/folly,guker/folly,floxard/folly,bikong2/folly,loversInJapan/folly,floxard/folly,bikong2/folly,mqeizi/folly,yangjin-unique/folly,loversInJapan/folly,nickhen/folly,floxard/folly,loversInJapan/folly,Orvid/folly,xzmagic/folly,mqeizi/folly,nickhen/folly,sakishum/folly,facebook/folly,clearlylin/folly,KSreeHarsha/folly,tomhughes/folly,alexst07/folly,bikong2/folly,doctaweeks/folly,renyinew/folly,Hincoin/folly,CJstar/folly,colemancda/folly,Orvid/folly,tempbottle/folly,brunomorishita/folly,guker/folly,Hincoin/folly,PoisonBOx/folly,loversInJapan/folly,sonnyhu/folly,mqeizi/folly,facebook/folly,bikong2/folly,clearlylin/folly,arg0/folly,Eagle-X/folly,bobegir/folly,yangjin-unique/folly,doctaweeks/folly,sonnyhu/folly,leolujuyi/folly,gavioto/folly,upsoft/folly,SeanRBurton/folly,cole14/folly,kernelim/folly,wildinto/folly,gaoyingie/folly,SammyK/folly,hongliangzhao/folly,fw1121/folly,colemancda/folly,nickhen/folly,theiver9827/folly,sonnyhu/folly,cole14/folly,renyinew/folly,chjp2046/folly,yangjin-unique/folly,theiver9827/folly,theiver9827/folly,chjp2046/folly,Eagle-X/folly,SeanRBurton/folly,stonegithubs/folly,CJstar/folly,rklabs/folly,Eagle-X/folly,CJstar/folly,sonnyhu/folly,tempbottle/folly,tomhughes/folly,wildinto/folly,guker/folly,juniway/folly,xzmagic/folly,raphaelamorim/folly,doctaweeks/folly,zhiweicai/folly,constantine001/folly,hongliangzhao/folly,hongliangzhao/folly,gavioto/folly,charsyam/folly,upsoft/folly,bowlofstew/folly,rklabs/folly,raphaelamorim/folly,sakishum/folly,nickhen/folly,tempbottle/folly,gavioto/folly,gavioto/folly,Orvid/folly,loversInJapan/folly,zhiweicai/folly,facebook/folly,reddit/folly