Add null check in SmartDialCursorLoader.releaseResources

Bug: 11474252
Change-Id: Id5a64aa72790bddef9e8fd2d4661635bd2eb6f44
diff --git a/src/com/android/dialer/dialpad/SmartDialCursorLoader.java b/src/com/android/dialer/dialpad/SmartDialCursorLoader.java
index a13ecd8..3690796 100644
--- a/src/com/android/dialer/dialpad/SmartDialCursorLoader.java
+++ b/src/com/android/dialer/dialpad/SmartDialCursorLoader.java
@@ -162,6 +162,8 @@
     }
 
     private void releaseResources(Cursor cursor) {
-        cursor.close();
+        if (cursor != null) {
+            cursor.close();
+        }
     }
 }