tests: Clean per test created buckets (#2717)
tests: Clean per test created buckets (#2717)

In addition to the general bucket name created for functinal tests,
some tests inside this latter creates separated buckets but remove
them using rm command which does not support removing buckets anymore.
krisis/mc,balamurugana/mc,vadmeste/mc,vadmeste/mc,krisis/mc,minio/mc,minio/mc,balamurugana/mc