(OgvAudio.TryOpen): don't dispose of intermediate stream.

ArcFormats/AudioOGV.cs

@@ -52,15 +52,8 @@ namespace GameRes.Formats.ShiinaRio
                 return null;
 
             var input = new StreamRegion (file, file.Position);
-            try
+            return new OggInput (input);
-            {
+            // input is left undisposed in case of exception.
-                return new OggInput (input);
-            }
-            catch
-            {
-                input.Dispose();
-                throw;
-            }
         }
     }
 }