[test] [NFC] cleanup aligned_storage test

* `s/"" )/"")/g`
* Don't redundantly test triviality for `TEST_STD_VER > 17`

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@329618 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed