update_engine: fixed remaining linter and some spelling errors

Fixed remaining errors from cpplint as well as some spelling errors
mostly in comments.

BUG=None
TEST=FEATURES=test emerge-link update_engine

Change-Id: I484988ab846ac5a3c68c016ddccfb247f225ec27
Reviewed-on: https://chromium-review.googlesource.com/208897
Reviewed-by: Alex Vakulenko <avakulenko@chromium.org>
Commit-Queue: Alex Vakulenko <avakulenko@chromium.org>
Tested-by: Alex Vakulenko <avakulenko@chromium.org>
diff --git a/action_processor.h b/action_processor.h
index 61fd29f..adc4781 100644
--- a/action_processor.h
+++ b/action_processor.h
@@ -17,7 +17,7 @@
 // a big thanks to that team for their high quality design, implementation,
 // and documentation.
 
-// See action.h for an overview of this class and other other Action* classes.
+// See action.h for an overview of this class and other Action* classes.
 
 // An ActionProcessor keeps a queue of Actions and processes them in order.
 
@@ -67,7 +67,7 @@
   // they'll be processed.
   std::deque<AbstractAction*> actions_;
 
-  // A pointer to the currrently processing Action, if any.
+  // A pointer to the currently processing Action, if any.
   AbstractAction* current_action_;
 
   // A pointer to the delegate, or NULL if none.