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/p2p_manager_unittest.cc b/p2p_manager_unittest.cc
index af83d4a..f76e47c 100644
--- a/p2p_manager_unittest.cc
+++ b/p2p_manager_unittest.cc
@@ -112,7 +112,7 @@
   EXPECT_TRUE(utils::RecursiveUnlinkDir(temp_dir));
 }
 
-// Check that IsP2PEnabled() corrresponds to the value of the crosh
+// Check that IsP2PEnabled() corresponds to the value of the crosh
 // flag if Enterprise Policy indicates that p2p is not to be used.
 TEST_F(P2PManagerTest, P2PEnabledEnterpriseSettingFalse) {
   string temp_dir;