RDMA/mlx5: remove variable i

Variable i is just being incremented and it's never used
anywhere else. The variable and the increment are redundant so
remove it.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Message-Id: <20221024133756.2158497-1-colin.i.king@gmail.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>