Revert "Hold mutex for transactional operations"
Revert "Hold mutex for transactional operations"

This reverts commit 58c3be19cd8de7e3f55a14e5cfa1c0ba55aa068d.

minio/minio-go,donatello/minio-go,awwalker/minio-go,abperiasamy/minio-go,harshavardhana/minio-go,dudymas/minio-go