Revert "char: misc: add test cases"

This reverts commit 45f0de4.

It breaks the build on many systems, so revert it for now.

Link: https://lore.kernel.org/r/20250501164501.0fc0ab68@canb.auug.org.au
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: gregkh