Since the parentheses are required due to precedence, then they are not there to show "I intend this assignment to happen". That would have to be:

  if ((options == (__WCLONE|__WALL)) && ((current->uid = 0)))

As an aside, note that this particular case also has the problem that the assignment expression makes the entire test expression false, which is suspicious. If an assignment expression occurs in the controlling expression of a selection or iteration statement, such that the entire expression is always true or false as a result, that should probably be warned about no matter how many parentheses have been heaped on to the assignment.