simplewallet: fix warnings about useless std::move

src/simplewallet/simplewallet.cpp

@@ -4383,7 +4383,7 @@ boost::optional<epee::wipeable_string> simple_wallet::new_wallet(const boost::pr
   }
   success_msg_writer() << "**********************************************************************";
 
-  return std::move(password);
+  return password;
 }
 //----------------------------------------------------------------------------------------------------
 boost::optional<epee::wipeable_string> simple_wallet::new_wallet(const boost::program_options::variables_map& vm,
@@ -4432,7 +4432,7 @@ boost::optional<epee::wipeable_string> simple_wallet::new_wallet(const boost::pr
   }
 
 
-  return std::move(password);
+  return password;
 }
 
 //----------------------------------------------------------------------------------------------------
@@ -4475,7 +4475,7 @@ boost::optional<epee::wipeable_string> simple_wallet::new_wallet(const boost::pr
     return {};
   }
 
-  return std::move(password);
+  return password;
 }
 //----------------------------------------------------------------------------------------------------
 boost::optional<epee::wipeable_string> simple_wallet::new_wallet(const boost::program_options::variables_map& vm,
@@ -4530,7 +4530,7 @@ boost::optional<epee::wipeable_string> simple_wallet::new_wallet(const boost::pr
     return {};
   }
 
-  return std::move(password);
+  return password;
 }
 //----------------------------------------------------------------------------------------------------
 boost::optional<epee::wipeable_string> simple_wallet::open_wallet(const boost::program_options::variables_map& vm)
@@ -4633,7 +4633,7 @@ boost::optional<epee::wipeable_string> simple_wallet::open_wallet(const boost::p
     tr("Use the \"help\" command to see the list of available commands.\n") <<
     tr("Use \"help <command>\" to see a command's documentation.\n") <<
     "**********************************************************************";
-  return std::move(password);
+  return password;
 }
 //----------------------------------------------------------------------------------------------------
 bool simple_wallet::close_wallet()