Rename ActionExitCode to ErrorCode

Nowadays ActionExitCode is used throughout the codebase so use a more
generic name to reflect this.

BUG=chromium:216507
TEST=unit tests pass

Change-Id: I23d1d7e2676443251dbc42ed137fd018aadfa8a3
Reviewed-on: https://gerrit.chromium.org/gerrit/49512
Reviewed-by: Don Garrett <dgarrett@chromium.org>
Commit-Queue: David Zeuthen <zeuthen@chromium.org>
Tested-by: David Zeuthen <zeuthen@chromium.org>
diff --git a/filesystem_copier_action.h b/filesystem_copier_action.h
index 366ae40..acbdd05 100644
--- a/filesystem_copier_action.h
+++ b/filesystem_copier_action.h
@@ -91,7 +91,7 @@
   // Cleans up all the variables we use for async operations and tells the
   // ActionProcessor we're done w/ |code| as passed in. |cancelled_| should be
   // true if TerminateProcessing() was called.
-  void Cleanup(ActionExitCode code);
+  void Cleanup(ErrorCode code);
 
   // Determine, if possible, the source file system size to avoid copying the
   // whole partition. Currently this supports only the root file system assuming