dfa: don't report parenthesized condition (IDEA-27427)

java/java-tests/testData/inspection/dataFlow/fixture/NoParenthesesWarnings.java

@@ -0,0 +1,7 @@
+class Fun {
+  void smthComplex() {
+    Object n  = new Integer(1);
+    String result = ((<warning descr="Condition 'n != null' is always 'true'">n != null</warning>) ? n.toString() : "");
+  }
+
+}