net/mlx5e: Fix operation precedence bug in port timestamping napi_poll context

In the Linux kernel, the following vulnerability has been resolved:

net/mlx5e: Fix operation precedence bug in port timestamping napi_poll context

Indirection (*) is of lower precedence than postfix increment (++). Logic

in napi_poll context would cause an out-of-bound read by first increment

the pointer address by byte address space and then dereference the value.

Rather, the intended logic was to dereference first and then increment the

underlying value.