Fix typo that happened during rebasing

I changed the type of this functions returned value but forgot to change
the check.

It happens to work before anyway, because eventually the interleaved
updates will get transferred at the beginning of the next render phase.
But this is more logically consistent.

Author: acdlite

packages/react-reconciler/src/ReactFiberWorkLoop.new.js

@@ -732,7 +732,7 @@ export function isInterleavedUpdate(fiber: Fiber, lane: Lane) {
       // defensive coding measure in case a new update comes in between when
       // rendering has finished and when the interleaved updates are transferred
       // to the main queue.
-      hasInterleavedUpdates() !== null) &&
+      hasInterleavedUpdates()) &&
     (fiber.mode & ConcurrentMode) !== NoMode &&
     // If this is a render phase update (i.e. UNSAFE_componentWillReceiveProps),
     // then don't treat this as an interleaved update. This pattern is

packages/react-reconciler/src/ReactFiberWorkLoop.old.js

@@ -732,7 +732,7 @@ export function isInterleavedUpdate(fiber: Fiber, lane: Lane) {
       // defensive coding measure in case a new update comes in between when
       // rendering has finished and when the interleaved updates are transferred
       // to the main queue.
-      hasInterleavedUpdates() !== null) &&
+      hasInterleavedUpdates()) &&
     (fiber.mode & ConcurrentMode) !== NoMode &&
     // If this is a render phase update (i.e. UNSAFE_componentWillReceiveProps),
     // then don't treat this as an interleaved update. This pattern is