net/mlx5: Remove return statement exist at the end of void function

[ Upstream commit 9dee115b ]

void function return statements are not generally useful.

Signed-off-by: Wenpeng Liang <liangwenpeng@huawei.com>
Signed-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Stable-dep-of: 90538d23 ("net/mlx5: E-switch, Fix error handling for enabling roce")
Signed-off-by: Sasha Levin <sashal@kernel.org>