Fix warnings in search/test_flann_search.cpp
Fix warnings in search/test_flann_search.cpp

> test_flann_search.cpp:360:25: warning: comparison of integers of different signs: 'size_t' (aka 'unsigned long') and 'int' [-Wsign-compare]

jeppewalther/kinfu_segmentation,RufaelDev/pcc-mp3dg,closerbibi/pcl,wgapl/pcl,v4hn/pcl,sbec/pcl,lydhr/pcl,wgapl/pcl,drmateo/pcl,the-glu/pcl,krips89/pcl_newfeatures,chenxingzhe/pcl,simonleonard/pcl,nikste/pcl,mschoeler/pcl,srbhprajapati/pcl,DaikiMaekawa/pcl,lebronzhang/pcl,LZRS/pcl,shivmalhotra/pcl,v4hn/pcl,locnx1984/pcl,raydtang/pcl,the-glu/pcl,stefanbuettner/pcl,v4hn/pcl,ResByte/pcl,KevenRing/vlp,stefanbuettner/pcl,raydtang/pcl,zhangxaochen/pcl,shangwuhencc/pcl,fanxiaochen/mypcltest,chatchavan/pcl,drmateo/pcl,chenxingzhe/pcl,soulsheng/pcl,RufaelDev/pcc-mp3dg,raydtang/pcl,lebronzhang/pcl,Tabjones/pcl,Tabjones/pcl,starius/pcl,KevenRing/pcl,lebronzhang/pcl,ipa-rmb/pcl,lydhr/pcl,chenxingzhe/pcl,MMiknis/pcl,LZRS/pcl,stefanbuettner/pcl,mikhail-matrosov/pcl,shangwuhencc/pcl,cascheberg/pcl,Tabjones/pcl,fanxiaochen/mypcltest,sbec/pcl,stfuchs/pcl,pkuhto/pcl,mschoeler/pcl,krips89/pcl_newfeatures,zavataafnan/pcl-truck,shyamalschandra/pcl,jeppewalther/kinfu_segmentation,jeppewalther/kinfu_segmentation,starius/pcl,fanxiaochen/mypcltest,nikste/pcl,mikhail-matrosov/pcl,lydhr/pcl,v4hn/pcl,starius/pcl,chenxingzhe/pcl,lebronzhang/pcl,stfuchs/pcl,soulsheng/pcl,chatchavan/pcl,krips89/pcl_newfeatures,jeppewalther/kinfu_segmentation,cascheberg/pcl,starius/pcl,shyamalschandra/pcl,jakobwilm/pcl,simonleonard/pcl,nikste/pcl,raydtang/pcl,shivmalhotra/pcl,locnx1984/pcl,zavataafnan/pcl-truck,srbhprajapati/pcl,ResByte/pcl,damienjadeduff/pcl,3dtof/pcl,shyamalschandra/pcl,raydtang/pcl,3dtof/pcl,drmateo/pcl,mschoeler/pcl,zhangxaochen/pcl,jeppewalther/kinfu_segmentation,chenxingzhe/pcl,pkuhto/pcl,shivmalhotra/pcl,fanxiaochen/mypcltest,krips89/pcl_newfeatures,msalvato/pcl_kinfu_highres,pkuhto/pcl,ipa-rmb/pcl,closerbibi/pcl,damienjadeduff/pcl,damienjadeduff/pcl,fskuka/pcl,shyamalschandra/pcl,3dtof/pcl,v4hn/pcl,shangwuhencc/pcl,jakobwilm/pcl,damienjadeduff/pcl,simonleonard/pcl,KevenRing/pcl,the-glu/pcl,cascheberg/pcl,srbhprajapati/pcl,locnx1984/pcl,KevenRing/pcl,fskuka/pcl,KevenRing/vlp,msalvato/pcl_kinfu_highres,chatchavan/pcl,locnx1984/pcl,zhangxaochen/pcl,lydhr/pcl,stfuchs/pcl,simonleonard/pcl,3dtof/pcl,mikhail-matrosov/pcl,krips89/pcl_newfeatures,msalvato/pcl_kinfu_highres,stefanbuettner/pcl,soulsheng/pcl,msalvato/pcl_kinfu_highres,zavataafnan/pcl-truck,closerbibi/pcl,mschoeler/pcl,wgapl/pcl,KevenRing/vlp,jakobwilm/pcl,RufaelDev/pcc-mp3dg,zhangxaochen/pcl,locnx1984/pcl,DaikiMaekawa/pcl,msalvato/pcl_kinfu_highres,DaikiMaekawa/pcl,RufaelDev/pcc-mp3dg,shyamalschandra/pcl,fanxiaochen/mypcltest,pkuhto/pcl,KevenRing/pcl,cascheberg/pcl,MMiknis/pcl,Tabjones/pcl,ResByte/pcl,Tabjones/pcl,DaikiMaekawa/pcl,nikste/pcl,stfuchs/pcl,KevenRing/vlp,ResByte/pcl,lebronzhang/pcl,damienjadeduff/pcl,sbec/pcl,ipa-rmb/pcl,shivmalhotra/pcl,zhangxaochen/pcl,zavataafnan/pcl-truck,kanster/pcl,LZRS/pcl,fskuka/pcl,stefanbuettner/pcl,fskuka/pcl,jakobwilm/pcl,KevenRing/pcl,kanster/pcl,drmateo/pcl,LZRS/pcl,mikhail-matrosov/pcl,LZRS/pcl,srbhprajapati/pcl,RufaelDev/pcc-mp3dg,KevenRing/vlp,kanster/pcl,simonleonard/pcl,soulsheng/pcl,kanster/pcl,ResByte/pcl,the-glu/pcl,zavataafnan/pcl-truck,srbhprajapati/pcl,starius/pcl,fskuka/pcl,ipa-rmb/pcl,shivmalhotra/pcl,nikste/pcl,ipa-rmb/pcl,sbec/pcl,shangwuhencc/pcl,drmateo/pcl,sbec/pcl,DaikiMaekawa/pcl,closerbibi/pcl,shangwuhencc/pcl,lydhr/pcl,MMiknis/pcl,wgapl/pcl,closerbibi/pcl,chatchavan/pcl,stfuchs/pcl,wgapl/pcl,MMiknis/pcl,soulsheng/pcl,cascheberg/pcl,jakobwilm/pcl,3dtof/pcl,pkuhto/pcl,the-glu/pcl,mikhail-matrosov/pcl,MMiknis/pcl,mschoeler/pcl,kanster/pcl