include guard name cleanup for IndexedMemPool
include guard name cleanup for IndexedMemPool

Summary: Include guard had FOLLY_DETAIL_.. even though code is in folly

Test Plan: unit tests

Reviewed By: davejwatson@fb.com

FB internal diff: D1130269

@override-unit-failures

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