suspicious assignment to a by-value method receiver

[chavacava]

In the code below, m.Hash = nil (line 537) will not affect the original hash wrapper because it is passed as a by-value receiver.

minio-go/utils.go

Lines 528 to 538 in 8142170

	func (m hashWrapper) Close() {
	if m.isMD5 && m.Hash != nil {
	m.Reset()
	md5Pool.Put(m.Hash)
	}
	if m.isSHA256 && m.Hash != nil {
	m.Reset()
	sha256Pool.Put(m.Hash)
	}
	m.Hash = nil
	}

(Found with revive)