[test] Avoid spurious failure in debug-names-find.s. NFC.

Have llvm-dwarfdump take input from stdin to avoid leaking the host paths into
the tests, causing nondeterministic failures.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@330121 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed