Fix Get Valid Counts when the number of boxes is zero (#7229)
Fix Get Valid Counts when the number of boxes is zero (#7229)


dmlc/tvm,Laurawly/tvm-1,Laurawly/tvm-1,dmlc/tvm,Laurawly/tvm-1,Laurawly/tvm-1,dmlc/tvm,dmlc/tvm,Laurawly/tvm-1,dmlc/tvm,dmlc/tvm,Laurawly/tvm-1,Laurawly/tvm-1,Laurawly/tvm-1,Laurawly/tvm-1,Laurawly/tvm-1,dmlc/tvm,dmlc/tvm,dmlc/tvm