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/source/Host/common/SoftwareBreakpoint.cpp b/lldb/source/Host/common/SoftwareBreakpoint.cpp
index 3d57b7d..6cb8126 100644
--- a/lldb/source/Host/common/SoftwareBreakpoint.cpp
+++ b/lldb/source/Host/common/SoftwareBreakpoint.cpp
@@ -103,7 +103,7 @@
   // breakpoint.
   breakpoint_sp.reset(new SoftwareBreakpoint(process, addr, saved_opcode_bytes,
                                              bp_opcode_bytes, bp_opcode_size));
-  return Error();
+  return Error::success();
 }
 
 Error SoftwareBreakpoint::EnableSoftwareBreakpoint(
@@ -219,7 +219,7 @@
     log->Printf("SoftwareBreakpoint::%s addr = 0x%" PRIx64 " -- SUCCESS",
                 __FUNCTION__, addr);
 
-  return Error();
+  return Error::success();
 }
 
 // -------------------------------------------------------------------