README: fixes arch naming
README: fixes arch naming

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