net/mlx5e: alloc the correct size for indirection_rqt

The cited patch allocated the wrong size for the indirection_rqt table,
fix that.

Fixes: 2119bda6 ("net/mlx5e: allocate 'indirection_rqt' buffer dynamically")
CC: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>