fix react@15 warning, ref #1340

components/date-picker/RangePicker.jsx

@@ -123,14 +123,14 @@ export default class RangePicker extends React.Component {
                 <input
                   disabled={disabled}
                   onChange={props.handleInputChange}
-                  value={start && props.getFormatter().format(start)}
+                  value={start ? props.getFormatter().format(start) : ''}
                   placeholder={startPlaceholder}
                   className="ant-calendar-range-picker-input" />
                 <span className="ant-calendar-range-picker-separator"> ~ </span>
                 <input
                   disabled={disabled}
                   onChange={props.handleInputChange}
-                  value={end && props.getFormatter().format(end)}
+                  value={end ? props.getFormatter().format(end) : ''}
                   placeholder={endPlaceholder}
                   className="ant-calendar-range-picker-input" />
                 <span className="ant-calendar-picker-icon" />

components/date-picker/createPicker.jsx

@@ -105,7 +105,7 @@ export default function createPicker(TheCalendar) {
                     <input
                       disabled={props.disabled}
                       onChange={props.handleInputChange}
-                      value={value && props.getFormatter().format(value)}
+                      value={value ? props.getFormatter().format(value) : ''}
                       placeholder={placeholder}
                       className={props.pickerInputClass} />
                     <span className="ant-calendar-picker-icon" />