Fix incorrect formatting

Gets rid of this warning:

  error: adding 'int' to a string does not append to the string [-Werror,-Wstring-plus-int]

src/GameCommand.cpp

@@ -738,7 +738,7 @@ void GameCommand::ApplySelf( const vector<PlayerNumber> &vpns ) const
 			}
 			break;
 		default:
-			LuaHelpers::ReportScriptError("Invalid StyleType: " + m_pStyle->m_StyleType);
+			LuaHelpers::ReportScriptErrorFmt("Invalid StyleType: %d", m_pStyle->m_StyleType);
 		}
 	}
 	if( m_dc != Difficulty_Invalid )

src/MenuTimer.cpp

@@ -183,9 +183,8 @@ void MenuTimer::SetText( float fSeconds )
 		LuaHelpers::Push( L, fSeconds );
 
 		// call function with 1 argument and 1 result
-		RString Error= "Error running Text" + (i+1);
-		Error+= "FormatFunction: ";
-		LuaHelpers::RunScriptOnStack(L, Error, 1, 1, true);
+		RString errorMessage = ssprintf("Error running Text%dFormatFunction: ", i+1);
+		LuaHelpers::RunScriptOnStack(L, errorMessage, 1, 1, true);
 
 		RString sText;
 		LuaHelpers::Pop( L, sText );