There are cases where debugging clone_range ("smb2_duplicate_extents"
function) and in the future copy_range ("smb2_copychunk_range") can
be helpful. Add dynamic trace points for any errors in clone, and
a followon patch will add them for copychunk.

  "trace-cmd record -e smb3_clone_err"
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>