net/mlx4_core: Fix build failure introduced by the EQ pool changes
When CONFIG_RFS_ACCEL or SMP aren't set, we fail to build, fix it.
Also, avoid build warning as of unused function on that setup.
Fixes: c66fa19c405a ('net/mlx4: Add EQ pool') Reported-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Matan Barak <matanb@mellanox.com> Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>