mellanox/mlxsw: fix repeated words in comments

Delete the redundant word 'action'.
Delete the redundant word 'refer'.
Delete the redundant word 'for'.

Signed-off-by: Jilin Yuan <yuanjilin@cdjrlc.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>