Despite being advertised to user space application, the RSS inner
header flag was filtered by checks at the beginning of QP creation
routine.

Cc: <stable@vger.kernel.org> # 4.15
Fixes: 4d02ebd9 ("IB/mlx4: Fix RSS hash fields restrictions")
Fixes: 07d84f7b ("IB/mlx4: Add support to RSS hash for inner headers")
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>