update_engine: use error_code for std::filesystem am: a77e645f14 am: a88ba553e5

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/3217657

Change-Id: Ib0d46efddf40a0724498a344e159412494c492e2
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
diff --git a/common/prefs.cc b/common/prefs.cc
index 79d622f..77078cf 100644
--- a/common/prefs.cc
+++ b/common/prefs.cc
@@ -200,7 +200,12 @@
     return false;
   }
   // Copy the directory.
-  std::filesystem::copy(source_directory, destination_directory);
+  std::error_code e;
+  std::filesystem::copy(source_directory, destination_directory, e);
+  if (e) {
+    LOG(ERROR) << "failed to copy prefs to prefs_tmp: " << e.message();
+    return false;
+  }
 
   return true;
 }
@@ -209,7 +214,12 @@
   std::filesystem::path destination_directory(GetTemporaryDir());
 
   if (std::filesystem::exists(destination_directory)) {
-    return std::filesystem::remove_all(destination_directory);
+    std::error_code e;
+    std::filesystem::remove_all(destination_directory, e);
+    if (e) {
+      LOG(ERROR) << "failed to remove directory: " << e.message();
+      return false;
+    }
   }
   return true;
 }