Fix array copy error in Readdir and Readdirplus responses

System.arraycopy(this.entries, 0, entries, 0, entries.length);
it should be
System.arraycopy(entries, 0, this.entries, 0, entries.length);

Findbugs gives EI2 warning if directly assign entries to this.entries:
EI2: May expose internal representation by incorporating reference to mutable object (EI_EXPOSE_REP2)

This caused NFS to fail to return directory content.