Fix macos/clang compile failures in filterintra_test.cc.

Add missing ampersands in make_tuple() calls setting up
function pointers.

Change-Id: Ibb8e169e9f5822573c09f10639a4bfc3b5039495
diff --git a/test/filterintra_test.cc b/test/filterintra_test.cc
index ed442a7..d2b2735 100644
--- a/test/filterintra_test.cc
+++ b/test/filterintra_test.cc
@@ -110,15 +110,15 @@
 using std::tr1::make_tuple;
 
 const PredFuncMode kPredFuncMdArray[] = {
-  make_tuple(av1_filter_intra_predictor_c, av1_filter_intra_predictor_sse4_1,
+  make_tuple(&av1_filter_intra_predictor_c, &av1_filter_intra_predictor_sse4_1,
              FILTER_DC_PRED),
-  make_tuple(av1_filter_intra_predictor_c, av1_filter_intra_predictor_sse4_1,
+  make_tuple(&av1_filter_intra_predictor_c, &av1_filter_intra_predictor_sse4_1,
              FILTER_V_PRED),
-  make_tuple(av1_filter_intra_predictor_c, av1_filter_intra_predictor_sse4_1,
+  make_tuple(&av1_filter_intra_predictor_c, &av1_filter_intra_predictor_sse4_1,
              FILTER_H_PRED),
-  make_tuple(av1_filter_intra_predictor_c, av1_filter_intra_predictor_sse4_1,
+  make_tuple(&av1_filter_intra_predictor_c, &av1_filter_intra_predictor_sse4_1,
              FILTER_D153_PRED),
-  make_tuple(av1_filter_intra_predictor_c, av1_filter_intra_predictor_sse4_1,
+  make_tuple(&av1_filter_intra_predictor_c, &av1_filter_intra_predictor_sse4_1,
              FILTER_PAETH_PRED),
 };