Remove duplicated code in CommandObjectQuit

[teemperor]

Summary

We already have the same check directly before, so this code can never be
reached (as seen in the test coverage).

[davide]

Sure.

source/Commands/CommandObjectQuit.cpp

bool CommandObjectQuit::DoExecute(Args &command, CommandReturnObject &result) {
 
   if (command.GetArgumentCount() > 1) {
     result.AppendError("Too many arguments for 'quit'. Only an optional exit "
                        "code is allowed");
     result.SetStatus(eReturnStatusFailed);
     return false;
   }
 
-  if (command.GetArgumentCount() > 1) {
-    result.AppendError("Too many arguments for 'quit'. Only an optional exit "
-                       "code is allowed");
-    result.SetStatus(eReturnStatusFailed);
-    return false;
-  }
-
   // We parse the exit code argument if there is one.
   if (command.GetArgumentCount() == 1) {
     llvm::StringRef arg = command.GetArgumentAtIndex(0);
     int exit_code;
     if (arg.getAsInteger(/*autodetect radix*/ 0, exit_code)) {
       lldb_private::StreamString s;
       std::string arg_str = arg.str();
       s.Printf("Couldn't parse '%s' as integer for exit code.", arg_str.data());