ikmeans_elkan: fixed signed / unsigned comparison warning
ikmeans_elkan: fixed signed / unsigned comparison warning

j-bo/vlfeat,mylxiaoyi/vlfeat,vlfeat/vlfeat,cvfish/vlfeat,richarddzh/vlfeat,CansenJIANG/vlfeat,WangDequan/vlfeat,mylxiaoyi/vlfeat,WangDequan/vlfeat,WangDequan/vlfeat,qubick/vlfeat,rxl194/vlfeat,mylxiaoyi/vlfeat,j-bo/vlfeat,WangDequan/vlfeat,rxl194/vlfeat,hongzhili/vlfeat,qubick/vlfeat,rxl194/vlfeat,vlfeat/vlfeat,hongzhili/vlfeat,CansenJIANG/vlfeat,j-bo/vlfeat,richarddzh/vlfeat,cvfish/vlfeat,richarddzh/vlfeat,hongzhili/vlfeat,qubick/vlfeat,hongzhili/vlfeat,CansenJIANG/vlfeat,erexhepa/vlfeat,richarddzh/vlfeat,qubick/vlfeat,vlfeat/vlfeat,j-bo/vlfeat,WangDequan/vlfeat,mylxiaoyi/vlfeat,qubick/vlfeat,vlfeat/vlfeat,erexhepa/vlfeat,WangDequan/vlfeat,mylxiaoyi/vlfeat,vlfeat/vlfeat,CansenJIANG/vlfeat,qubick/vlfeat,CansenJIANG/vlfeat,cvfish/vlfeat,erexhepa/vlfeat,erexhepa/vlfeat,rxl194/vlfeat,richarddzh/vlfeat,hongzhili/vlfeat,cvfish/vlfeat,richarddzh/vlfeat,CansenJIANG/vlfeat,mylxiaoyi/vlfeat,rxl194/vlfeat,vlfeat/vlfeat,rxl194/vlfeat,erexhepa/vlfeat,cvfish/vlfeat,j-bo/vlfeat,cvfish/vlfeat,hongzhili/vlfeat,erexhepa/vlfeat