Fix extraneous whitespace around keywords.

def fix_e271(self, result):
        """Fix extraneous whitespace around keywords."""
        line_index = result['line'] - 1
        target = self.source[line_index]
        offset = result['column'] - 1

        fixed = fix_whitespace(target,
                               offset=offset,
                               replacement=' ')

        if fixed == target:
            return []
        else:
            self.source[line_index] = fixed