[riscv-port-jdk17u:riscv-port] RFR: 8287552: riscv: Fix comment typo in li64

[Feilong Jiang]

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On Tue, 7 Mar 2023 07:46:02 GMT, Dingli Zhang <dzhang at openjdk.org> wrote:

> Please review this backport to riscv-port-jdk17u.
> Backport of [JDK-8287552](https://bugs.openjdk.java.net/browse/JDK-8287552). Applies cleanly.
> 
> Testing:
> 
> - Tier1 passed without new failure on unmacthed (release).

Marked as reviewed by fjiang (no project role).

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PR: https://git.openjdk.org/riscv-port-jdk17u/pull/7