Steps to reproduce the issue

• Open an admin table view (i.e. Content > Articles)
• Enter a search string in the search input
• Start the search
• Click the 'Clear' button

Expected result

The search input gets cleared.

Actual result

The input doesn't get cleared.

System information (as much as possible)

• PHP Version: 7.1.6
• Joomla! Version: Joomla! 4.0.0-dev
• Browser: 60.0.3112.113

Additional comments

Clicking the clear button throws a JS exception:

searchtools.min.js?5db449f2a258ef8a1cac138587e3af6d:1 Uncaught TypeError: Cannot read property 'value' of null
    at t.checkFilter (searchtools.min.js?5db449f2a258ef8a1cac138587e3af6d:1)
    at searchtools.min.js?5db449f2a258ef8a1cac138587e3af6d:1
    at Array.forEach (<anonymous>)
    at t.clear (searchtools.min.js?5db449f2a258ef8a1cac138587e3af6d:1)
    at HTMLButtonElement.<anonymous> (searchtools.min.js?5db449f2a258ef8a1cac138587e3af6d:1)