init/Kconfig: Adjust fixed clang version for __builtin_counted_by_ref

init/Kconfig: Adjust fixed clang version for __builtin_counted_by_ref

Commit d39a1d7486d9 ("compiler_types: Disable __builtin_counted_by_ref
for Clang") used 22.0.0 as the fixed version for a compiler crash but
the fix was only merged in main (23.0.0) and release/22.x (22.1.0). With
the current fixed version number, prerelease or Android LLVM 22 builds
will still be able to hit the compiler crash when building the kernel.
This can be particularly disruptive when bisecting LLVM.

Use 21.1.0 as the fixed version number to ensure the fix for this crash
is always present.

Fixes: d39a1d7486d9 ("compiler_types: Disable __builtin_counted_by_ref for Clang")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Link: https://patch.msgid.link/20260223-fix-clang-version-builtin-counted-by-ref-v1-1-3ea478a24f0a@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>