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>
diff --git a/filesystem_copier_action_unittest.cc b/filesystem_copier_action_unittest.cc
index 3e5f1b9..4d67b5e 100644
--- a/filesystem_copier_action_unittest.cc
+++ b/filesystem_copier_action_unittest.cc
@@ -78,6 +78,7 @@
   }
   bool ran() const { return ran_; }
   ErrorCode code() const { return code_; }
+
  private:
   GMainLoop* loop_;
   FilesystemCopierAction* action_;
@@ -420,7 +421,7 @@
     EXPECT_EQ(kint64max, action.filesystem_size_);
     {
       int fd = HANDLE_EINTR(open(img.c_str(), O_RDONLY));
-      EXPECT_TRUE(fd > 0);
+      EXPECT_GT(fd, 0);
       ScopedFdCloser fd_closer(&fd);
       action.DetermineFilesystemSize(fd);
     }