Fix FP ignoredReturnValue (#4783)

Author: chrchr-github

lib/checkfunctions.cpp

@@ -254,7 +254,7 @@ void CheckFunctions::checkIgnoredReturnValue()
 
             const Token *parent = tok->next()->astParent();
             while (Token::Match(parent, "%cop%")) {
-                if (Token::Match(parent, "<<|>>") && !parent->astParent())
+                if (Token::Match(parent, "<<|>>|*") && !parent->astParent())
                     break;
                 parent = parent->astParent();
             }

test/testfunctions.cpp

@@ -1451,6 +1451,10 @@ class TestFunctions : public TestFixture {
               "}", "test.cpp", &settings2);
         ASSERT_EQUALS("[test.cpp:2]: (warning) Return value of function mystrcmp() is not used.\n", errout.str());
 
+        check("void f(std::vector<int*> v) {\n"
+              "    delete *v.begin();\n"
+              "}\n");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void checkIgnoredErrorCode() {