[lldb] A few small changes to HandleProgressEvent

Of course I only noticed these things *after* landing the original
patch...

 - Flush the output after clearing the line.
 - Move up the printing the carriage return to avoid duplication.
 - Use hexadecimal instead of octal for escape codes.

(cherry picked from commit e618eb8)

Author: JDevlieghere

lldb/source/Core/Debugger.cpp

@@ -1839,9 +1839,13 @@ void Debugger::HandleProgressEvent(const lldb::EventSP &event_sp) {
   if (!output.GetIsInteractive() || !output.GetIsTerminalWithColors())
     return;
 
+  // Print over previous line, if any.
+  output.Printf("\r");
+
   if (data->GetCompleted()) {
     // Clear the current line.
-    output.Printf("\33[2K\r");
+    output.Printf("\x1B[2K");
+    output.Flush();
     return;
   }
 
@@ -1851,9 +1855,6 @@ void Debugger::HandleProgressEvent(const lldb::EventSP &event_sp) {
     output.Printf(
         "%s", ansi::FormatAnsiTerminalCodes(ansi_prefix, use_color).c_str());
 
-  // Print over previous line, if any.
-  output.Printf("\r");
-
   // Print the progress message.
   std::string message = data->GetMessage();
   if (data->GetTotal() != UINT64_MAX) {