tools/nolibc: use intmax definitions from compiler

The printf format checking in the compiler uses the intmax types from
the compiler, not libc. This can lead to compiler errors.

Instead use the types already provided by the compiler.

Example issue with clang 19 for arm64:

nolibc-test.c:30:2: error: format specifies type 'uintmax_t' (aka 'unsigned long') but the argument has type 'uintmax_t' (aka 'unsigned long long') [-Werror,-Wformat]

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Acked-by: Willy Tarreau <w@1wt.eu>