update test

Author: ludviggunne

test/testother.cpp

@@ -2909,7 +2909,7 @@ class TestOther : public TestFixture {
         check("struct X { int a[5]; }; extern \"C\" void f(X v) { }");
         ASSERT_EQUALS("", errout_str());
 
-        check("struct X { int a[5]; }; void f(const X v);");
+        check("struct X { int a[5]; }; void f(const X v) { (void) v; }");
         ASSERT_EQUALS("[test.cpp:1:40]: (performance) Function parameter 'v' should be passed by const reference. [passedByValue]\n", errout_str());
 
         check("extern \"C\" { struct X { int a[5]; }; void f(const X v); }");