recordable: update recording_ in stopRecording()

Currently the recording_ variable isn't updated by stopRecording()
in the Recordable class.

This patch addresses this issue.

Change-Id: I8400eac2380890c9a9a897258e2ccc84d80f0452
Reviewed-by: Philippe Gorley <philippe.gorley@savoirfairelinux.com>

src/media/recordable.cpp

@@ -68,6 +68,7 @@ Recordable::stopRecording()
         return;
     if (recorder_)
         recorder_->stopRecording();
+    recording_ = false;
     recorder_.reset();
 }