Do not send SMB3 SET_INFO request if nothing is changing

commit 18dd8e1a65ddae2351d0f0d6dd4a334f441fc5fa upstream.

[CIFS] We had cases where we sent a SMB2/SMB3 setinfo request with all
timestamp (and DOS attribute) fields marked as 0 (ie do not change)
e.g. on chmod or chown.

Signed-off-by: Steve French <steve.french@primarydata.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>