smb: client: set ATTR_TEMPORARY with O_TMPFILE | O_EXCL

smb: client: set ATTR_TEMPORARY with O_TMPFILE | O_EXCL

Set ATTR_TEMPORARY attribute on temporary delete-on-close files when
O_EXCL is specified in conjunction with O_TMPFILE to let some servers
cache as much data as possible and possibly never persist them into
storage, thereby improving performance.

Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Cc: David Howells <dhowells@redhat.com>
Cc: linux-cifs@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>