mlx4_core: Fix mtt profile issue

Num mtts from profile is really the number of mtt segments.
Thus, in make profile, to get the proper number of MTT entries,
must multiply num_mtts by mtts per segment.

Signed-off-by: Marcel Apfelbaum <marcela@dev.mellanox.co.il>
Reviewed-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>