[clang] [clang] Fix of test 'ctu-import-type-decl-definition.c' (NFC) (PR #157038)

[Balázs Kéri via cfe-commits]

balazske wrote:

The test (which is fixed here) was added in #156056 which was already a fix of the same test in #155375.

https://github.com/llvm/llvm-project/pull/157038