net/mlx4_en: fix a memory leak bug

net/mlx4_en: fix a memory leak bug

In mlx4_en_config_rss_steer(), 'rss_map->indir_qp' is allocated through
kzalloc(). After that, mlx4_qp_alloc() is invoked to configure RSS
indirection. However, if mlx4_qp_alloc() fails, the allocated
'rss_map->indir_qp' is not deallocated, leading to a memory leak bug.

To fix the above issue, add the 'qp_alloc_err' label to free
'rss_map->indir_qp'.

Fixes: 0f063b8aeab6 ("net/mlx4_en: Optimized single ring steering")
Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>