invalid_file_test.cc is only for VP9 decoder

Fix --disable-vp9 build

https://code.google.com/p/webm/issues/detail?id=857

Change-Id: I98eacab5aa4aa9a657647acadd8ce2bd1a4590c0
diff --git a/test/test.mk b/test/test.mk
index abf815c..97b8aba 100644
--- a/test/test.mk
+++ b/test/test.mk
@@ -30,6 +30,7 @@
 LIBVPX_TEST_SRCS-$(CONFIG_VP8_ENCODER) += keyframe_test.cc
 
 LIBVPX_TEST_SRCS-$(CONFIG_VP9_DECODER) += external_frame_buffer_test.cc
+LIBVPX_TEST_SRCS-$(CONFIG_VP9_DECODER) += invalid_file_test.cc
 LIBVPX_TEST_SRCS-$(CONFIG_VP9_DECODER) += user_priv_test.cc
 LIBVPX_TEST_SRCS-$(CONFIG_VP9_ENCODER) += active_map_test.cc
 LIBVPX_TEST_SRCS-$(CONFIG_VP9_ENCODER) += borders_test.cc
@@ -60,7 +61,6 @@
 endif
 
 LIBVPX_TEST_SRCS-$(CONFIG_DECODERS)    += decode_api_test.cc
-LIBVPX_TEST_SRCS-$(CONFIG_DECODERS)    += invalid_file_test.cc
 LIBVPX_TEST_SRCS-$(CONFIG_DECODERS)    += test_vector_test.cc
 
 # Currently we only support decoder perf tests for vp9. Also they read from WebM