Switch the handful of std::endl users over to the predominant "\n".

(cherry picked from commit f6ee3605a88dec1114c60963a626aeec29d47220)

Change-Id: I8124de153cb34657d22fb8bbca37864ff2f7abe0
diff --git a/src/thread.cc b/src/thread.cc
index fe38c8e..01e0771 100644
--- a/src/thread.cc
+++ b/src/thread.cc
@@ -1788,7 +1788,7 @@
     String* msg = exception->GetDetailMessage();
     std::string str_msg(msg != NULL ? msg->ToModifiedUtf8() : "");
     DumpStack(LOG(INFO) << "Delivering exception: " << PrettyTypeOf(exception)
-                        << ": " << str_msg << std::endl);
+                        << ": " << str_msg << "\n");
   }
 
   Context* long_jump_context = GetLongJumpContext();