net/mlx5: fix potential memory leak in mlx5e_init_rep_rx

The memory pointed to by the priv->rx_res pointer is not freed in the error
path of mlx5e_init_rep_rx, which can lead to a memory leak. Fix by freeing
the memory in the error path, thereby making the error path identical to
mlx5e_cleanup_rep_rx().

Fixes: af8bbf73

 ("net/mlx5e: Convert mlx5e_flow_steering member of mlx5e_priv to pointer")
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>