Fix potential unintialized variable yuvformat

Change-Id: If0a77855d98b45769a154b25d6535f30cd41536a
diff --git a/media/libstagefright/CameraSourceTimeLapse.cpp b/media/libstagefright/CameraSourceTimeLapse.cpp
index 44d159a..227e090 100644
--- a/media/libstagefright/CameraSourceTimeLapse.cpp
+++ b/media/libstagefright/CameraSourceTimeLapse.cpp
@@ -286,7 +286,8 @@
     YUVImage::YUVFormat yuvFormat;
     if (srcFormat == OMX_COLOR_FormatYUV420SemiPlanar) {
         yuvFormat = YUVImage::YUV420SemiPlanar;
-    } else if (srcFormat == OMX_COLOR_FormatYUV420Planar) {
+    } else {
+        CHECK_EQ(srcFormat, OMX_COLOR_FormatYUV420Planar);
         yuvFormat = YUVImage::YUV420Planar;
     }