Make the Error class constructor protected

This is forcing to use Error::success(), which is in a wide majority
of cases a lot more readable.

Differential Revision: https://reviews.llvm.org/D26481

llvm-svn: 286561
diff --git a/lldb/tools/lldb-server/lldb-platform.cpp b/lldb/tools/lldb-server/lldb-platform.cpp
index 21d422c..5bbe1ce 100644
--- a/lldb/tools/lldb-server/lldb-platform.cpp
+++ b/lldb/tools/lldb-server/lldb-platform.cpp
@@ -130,7 +130,7 @@
                  file_spec.GetPath().c_str(), err_code.message().c_str());
 
   tmp_file_remover.releaseFile();
-  return Error();
+  return Error::success();
 }
 
 //----------------------------------------------------------------------