Fix unused variables in tests to placate scan-build. Patch from Steve MacKenzie.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@220154 91177308-0d34-0410-b5e6-96231b3b80d8

test/containers/sequences/array/array.data/data.pass.cpp

@@ -30,5 +30,6 @@ int main()
         typedef std::array<T, 0> C;
         C c = {};
         T* p = c.data();
+        (void)p; // to placate scan-build
     }
 }

test/containers/sequences/array/array.data/data_const.pass.cpp

@@ -30,5 +30,6 @@ int main()
         typedef std::array<T, 0> C;
         const C c = {};
         const T* p = c.data();
+        (void)p; // to placate scan-build
     }
 }