libchromeos: void OsReleaseReader.Load()

Previously OsReleaseReader returned a bool, which meant that code that
called load wanted to CHECK the return values and possibly log warning
messages, etc. This was unecessary since OsReleaseReader.Load never
returns false.

TEST=unittests
BUG=none

Change-Id: I7064c6a788897b5d5c687d6c9c5f4e03d4ca21a7
Reviewed-on: https://chromium-review.googlesource.com/223990
Reviewed-by: Bertrand Simonnet <bsimonnet@google.com>
Commit-Queue: Nathan Bullock <nathanbullock@google.com>
Tested-by: Nathan Bullock <nathanbullock@google.com>
diff --git a/metrics/uploader/system_profile_cache.cc b/metrics/uploader/system_profile_cache.cc
index b08fbd9..cbb8051 100644
--- a/metrics/uploader/system_profile_cache.cc
+++ b/metrics/uploader/system_profile_cache.cc
@@ -150,10 +150,9 @@
   chromeos::OsReleaseReader reader;
   if (testing_) {
     base::FilePath root(config_root_);
-    CHECK(reader.LoadTestingOnly(root)) << "Failed to load os-release fields "
-                                        "from" << root.value();
+    reader.LoadTestingOnly(root);
   } else {
-    CHECK(reader.Load()) << "Failed to load os-release fields.";
+    reader.Load();
   }
 
   std::string id;