Make sure stagefright -o terminates even if we're using a raw audio source (such as .wav pcm)

Change-Id: Iec809df89e6b75706cf5b1ce21006c2e217e018f
diff --git a/cmds/stagefright/stagefright.cpp b/cmds/stagefright/stagefright.cpp
index 4a1d27b..8ab94ad 100644
--- a/cmds/stagefright/stagefright.cpp
+++ b/cmds/stagefright/stagefright.cpp
@@ -60,7 +60,7 @@
     return (int64_t)tv.tv_usec + tv.tv_sec * 1000000ll;
 }
 
-static void playSource(OMXClient *client, const sp<MediaSource> &source) {
+static void playSource(OMXClient *client, sp<MediaSource> &source) {
     sp<MetaData> meta = source->getFormat();
 
     const char *mime;
@@ -81,6 +81,8 @@
         }
     }
 
+    source.clear();
+
     status_t err = rawSource->start();
 
     if (err != OK) {