net/mlx5: E-Switch, remove redundant error handling

We don't need to handle error flow of esw_create_legacy_table() in the
same branch, it is already being handled directly after the if statement,
for both legacy and switchdev modes in one place.

Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>