[libcxx] [test] Fix whitespace, NFC.

test/std almost always uses spaces; now it is entirely tab-free.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@329978 91177308-0d34-0410-b5e6-96231b3b80d8

test/std/containers/test_compare.h

@@ -38,7 +38,7 @@ template <class C>
 class non_const_compare
 {
 // operator() deliberately not marked as 'const'
-    bool operator()(const C& x,const C&y) { return x < y; }
+    bool operator()(const C& x, const C& y) { return x < y; }
 };