Remove trailing whitespace in test suite. Approved by Marshall Clow.

llvm-svn: 271435
diff --git a/libcxx/test/std/utilities/function.objects/arithmetic.operations/plus.pass.cpp b/libcxx/test/std/utilities/function.objects/arithmetic.operations/plus.pass.cpp
index 3c093fc..ce544c7 100644
--- a/libcxx/test/std/utilities/function.objects/arithmetic.operations/plus.pass.cpp
+++ b/libcxx/test/std/utilities/function.objects/arithmetic.operations/plus.pass.cpp
@@ -29,7 +29,7 @@
     assert(f2(3,2) == 5);
     assert(f2(3.0, 2) == 5);
     assert(f2(3, 2.5) == 5.5);
-    
+
     constexpr int foo = std::plus<int> () (3, 2);
     static_assert ( foo == 5, "" );