Pressing = twice shouldn't clear the calculation result

Bug: 15517592
Change-Id: I682e6cf8d7b909b3712e5f604ea50edfc18ba883
diff --git a/src/com/android/calculator2/CalculatorActivity.java b/src/com/android/calculator2/CalculatorActivity.java
index a2bc4fd..cd386eb 100644
--- a/src/com/android/calculator2/CalculatorActivity.java
+++ b/src/com/android/calculator2/CalculatorActivity.java
@@ -177,9 +177,7 @@
     public void onButtonClick(View view) {
         switch (view.getId()) {
             case R.id.eq:
-                if (mCurrentState != CalculatorState.INPUT) {
-                    mFormulaEditText.getEditableText().clear();
-                } else {
+                if (mCurrentState == CalculatorState.INPUT) {
                     setState(CalculatorState.EVALUATE);
                     mEvaluator.evaluate(mFormulaEditText.getText(), this);
                 }