Error compiling libctf-regression test

[Nick Alcock]

On 20 Apr 2024, Alan Modra stated:

> Seen on 64-bit targets.

Interesting. I compile on a number of those targets and never saw this...

> ERROR: compilation of lookup program .../libctf-regression/gzrewrite.c failed
>
> 	* testsuite/libctf-regression/gzrewrite.c (main): Use %zu to
> 	print size_t values.
> 	* testsuite/libctf-regression/zrewrite.c (main): Likewise.

... but this is obviously correct anyway, thank you.