revert "POSIX: should not delete if a directory is not empty"
revert "POSIX: should not delete if a directory is not empty"

revert 0c75f15062c931d457fb52a079ca22fbb4679247

Reported:

Hi, about commit: 0c75f15062c931d457fb52a079ca22fbb4679247
POSIX: should not delete if a directory is not empty
It should still delete with a command like rm -rf "${path}"/  because it is a forced delete, but now it gets fail to delete non-empty folder: [...]
Can you enable the delete if it is forced?

chrislusf/seaweedfs,chrislusf/seaweedfs,chrislusf/seaweedfs,chrislusf/seaweedfs