net/mlx5e: fix a double-free in arfs_create_groups

net/mlx5e: fix a double-free in arfs_create_groups

When `in` allocated by kvzalloc fails, arfs_create_groups will free
ft->g and return an error. However, arfs_create_table, the only caller of
arfs_create_groups, will hold this error and call to
mlx5e_destroy_flow_table, in which the ft->g will be freed again.

Fixes: 1cabe6b0965e ("net/mlx5e: Create aRFS flow tables")
Signed-off-by: Zhipeng Lu <alexious@zju.edu.cn>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>