Fix an issue wherre error notification will not be sent after mediaplayer reset

bug - 3198642

Change-Id: Ieab13e12af9fdd0ad0873c522885e1350e7cd24c
diff --git a/media/libmedia/mediaplayer.cpp b/media/libmedia/mediaplayer.cpp
index 54b292c..a098d69 100644
--- a/media/libmedia/mediaplayer.cpp
+++ b/media/libmedia/mediaplayer.cpp
@@ -437,6 +437,9 @@
         } else {
             mCurrentState = MEDIA_PLAYER_IDLE;
         }
+        // setDataSource has to be called again to create a
+        // new mediaplayer.
+        mPlayer = 0;
         return ret;
     }
     clear_l();