Single-quotes to quote parentheses.

On Windows, neither "(" nor ")" are shell special characters, so -\( is passed
as-is to LLD. Because of that this test was failing on Windows.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@193905 91177308-0d34-0410-b5e6-96231b3b80d8