Revert "Memory pool dynamic slots allocations."

This reverts commit bbd10086fbaf128a061a0cd764a582bb7db1dbe6.

Forgot to add credit to "Matt W. Benjamin" <matt@linuxbox.com>"
Memory pool dynamic slots allocations. The pool was extended to enable its user to create memory slots dynamically

Signed-off-by: Matt W. Benjamin <matt@linuxbox.com>
Signed-off-by: Shlomo Pongratz <shlomop@mellanox.com>
Signed-off-by: Eyal Salomon <esalomon@mellanox.com>