Fix the CameraHardwareInterface::setPreviewWindow comment.

Change-Id: Ied7eb7872e581e23d9f6f02a551320cdd675e51e
diff --git a/include/camera/CameraHardwareInterface.h b/include/camera/CameraHardwareInterface.h
index 515d879..3a77dd1 100644
--- a/include/camera/CameraHardwareInterface.h
+++ b/include/camera/CameraHardwareInterface.h
@@ -87,7 +87,7 @@
 public:
     virtual ~CameraHardwareInterface() { }
 
-    /** Set the ISurface from which the preview buffers should be dequeued */
+    /** Set the ANativeWindow to which preview frames are sent */
     virtual status_t setPreviewWindow(const sp<ANativeWindow>& buf) = 0;
 
     /** Return the IMemoryHeap for the raw image heap */