RFR: 8315550: G1: Fix -Wconversion warnings in g1NUMA

[Thomas Schatzl]

On Fri, 1 Sep 2023 15:48:25 GMT, Albert Mingkun Yang <ayang at openjdk.org> wrote:

> Simple `int` to `uint` for NUMA node-id.
> 
> Possibly, `numa_get_leaf_groups` should accept `uint[]`. I will attempt that in another PR, as that will be mostly runtime, not G1 specific.

Seems good.

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Marked as reviewed by tschatzl (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/15541#pullrequestreview-1620092430