net/mlx5: Fixed a typo in a comment in esw_del_uc_addr()

Changed "managerss" to "managers".

Fixes: a1b3839a ("net/mlx5: E-Switch, Properly refer to the esw manager vport")
Signed-off-by: Qing Huang <qing.huang@oracle.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>