Fix to unit testing code.

* test_utils::ExpectVectorsEq() returns false if vector contents are not
  identical (conforming to the documentation in test_utils.h). This
  should clarify which of the ExpectVectorsEq() calls fail in the
  associated bug.

* Moved a buffer integrity test to a more sensible location.

BUG=chromium-os:29841
TEST=Unit tests run successfully

Change-Id: I1d8d679e3b42e9b90af7d906bb019feeecbb8e0e
Reviewed-on: https://gerrit.chromium.org/gerrit/22704
Reviewed-by: Don Garrett <dgarrett@chromium.org>
Tested-by: Gilad Arnold <garnold@chromium.org>
Commit-Ready: Gilad Arnold <garnold@chromium.org>
diff --git a/filesystem_copier_action_unittest.cc b/filesystem_copier_action_unittest.cc
index ccad03a..967ca20 100644
--- a/filesystem_copier_action_unittest.cc
+++ b/filesystem_copier_action_unittest.cc
@@ -211,12 +211,12 @@
   // Make sure everything in the out_image is there
   vector<char> a_out;
   EXPECT_TRUE(utils::ReadFile(a_dev, &a_out));
+  EXPECT_TRUE(ExpectVectorsEq(a_loop_data, a_out));
   if (!verify_hash) {
     vector<char> b_out;
     EXPECT_TRUE(utils::ReadFile(b_dev, &b_out));
     EXPECT_TRUE(ExpectVectorsEq(a_out, b_out));
   }
-  EXPECT_TRUE(ExpectVectorsEq(a_loop_data, a_out));
 
   EXPECT_TRUE(collector_action.object() == install_plan);
 }