AU: When checking if we've visited a file before, don't follow symlinks.

A bug caused a failure when a file existed on the old image that was a
symlink to a non-existent path. This CL fixes that bug.

BUG=chromium-os:12393
TEST=unittests/generated and tested a delta

Change-Id: Ifba711be2bfc3c1d96a4ed8536b16b5d7b8a0cae

Review URL: http://codereview.chromium.org/6551015
diff --git a/test_utils.cc b/test_utils.cc
index 3815d7b..85c73d7 100644
--- a/test_utils.cc
+++ b/test_utils.cc
@@ -211,12 +211,15 @@
   EXPECT_EQ(0, System(StringPrintf("echo T > %s/srchardlink0", kMountPath)));
   EXPECT_EQ(0, System(StringPrintf("ln %s/srchardlink0 %s/srchardlink1",
                                    kMountPath, kMountPath)));
+  EXPECT_EQ(0, System(StringPrintf("ln -s bogus %s/boguslink",
+                                   kMountPath)));
   EXPECT_EQ(0, System(StringPrintf("umount -d %s", kMountPath)));
 
   if (out_paths) {
     out_paths->clear();
     out_paths->push_back("");
     out_paths->push_back("/hi");
+    out_paths->push_back("/boguslink");
     out_paths->push_back("/hello");
     out_paths->push_back("/some_dir");
     out_paths->push_back("/some_dir/empty_dir");