Fixed a possible overflow in a test of allocator::max_size().

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@249349 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/std/utilities/memory/default.allocator/allocator.members/max_size.pass.cpp b/test/std/utilities/memory/default.allocator/allocator.members/max_size.pass.cpp
index 6ec9339..1010938 100644
--- a/test/std/utilities/memory/default.allocator/allocator.members/max_size.pass.cpp
+++ b/test/std/utilities/memory/default.allocator/allocator.members/max_size.pass.cpp
@@ -22,6 +22,6 @@
 int main()
 {
     const std::allocator<int> a;
-    std::size_t M = a.max_size() * sizeof(int);
-    assert(M > 0xFFFF && M <= std::numeric_limits<std::size_t>::max());
+    std::size_t M = a.max_size();
+    assert(M > 0xFFFF && M <= (std::numeric_limits<std::size_t>::max() / sizeof(int)));
 }