kunit: executor: Remove const from kunit_filter_suites() allocation type

kunit: executor: Remove const from kunit_filter_suites() allocation type

In preparation for making the kmalloc family of allocators type aware,
we need to make sure that the returned type from the allocation matches
the type of the variable being assigned. (Before, the allocator would
always return "void *", which can be implicitly cast to any pointer type.)

The assigned type is "struct kunit_suite **" but the returned type will
be "struct kunit_suite * const *". Since it isn't generally possible
to remove the const qualifier, adjust the allocation type to match
the assignment.

Link: https://lore.kernel.org/r/20250426062433.work.124-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>