Fix bug #14302110 Settings crash on hitting back key from Wifi recent searches page

- prevent NPE on mSearchResultsFragment

Change-Id: I063ff17e3936be7e608a37bd6a787946b4a310fe
diff --git a/src/com/android/settings/SettingsActivity.java b/src/com/android/settings/SettingsActivity.java
index 56ee3ac..0a275fc 100644
--- a/src/com/android/settings/SettingsActivity.java
+++ b/src/com/android/settings/SettingsActivity.java
@@ -1229,7 +1229,7 @@
     @Override
     public boolean onQueryTextChange(String newText) {
         mSearchQuery = newText;
-        if (TextUtils.isEmpty(newText) && mSearchResultsFragment == null) {
+        if (TextUtils.isEmpty(newText) || mSearchResultsFragment == null) {
             return false;
         }
         return mSearchResultsFragment.onQueryTextChange(newText);