The gather and scatter operations did not use the correct message size
(Only did datatype size * com size). This did not correctly reflect the
total message size and prevents fine tuning within a com size. This
patch multiplies the value by the number of elements sent.
Signed-off-by: William Zhang <wilzhang@amazon.com>
(cherry picked from commit 50823fe9a9ef4f93e55ee2087b311303d49f90a8)
7922430c66