update_engine: fixed warnings from cpplint

Fixed all the cpplint warnings in update engine.

BUG=None
TEST=Unit tests still pass.

Change-Id: I285ae858eec8abe0b26ff203b99a42a200ceb71c
Reviewed-on: https://chromium-review.googlesource.com/204027
Reviewed-by: Alex Vakulenko <avakulenko@chromium.org>
Tested-by: Alex Vakulenko <avakulenko@chromium.org>
Commit-Queue: Alex Vakulenko <avakulenko@chromium.org>

install_plan.h

diff --git a/install_plan.h b/install_plan.h
index b6bf293..b30170e 100644
--- a/install_plan.h
+++ b/install_plan.h
@@ -95,7 +95,7 @@
 class InstallPlanAction : public Action<InstallPlanAction> {
  public:
   InstallPlanAction() {}
-  InstallPlanAction(const InstallPlan& install_plan):
+  explicit InstallPlanAction(const InstallPlan& install_plan):
     install_plan_(install_plan) {}
 
   virtual void PerformAction() {
@@ -116,7 +116,7 @@
  private:
   InstallPlan install_plan_;
 
-  DISALLOW_COPY_AND_ASSIGN (InstallPlanAction);
+  DISALLOW_COPY_AND_ASSIGN(InstallPlanAction);
 };
 
 }  // namespace chromeos_update_engine