8256426: Shenandoah: Remove superfluous assert is ShBS::load_reference_barrier()

Reviewed-by: shade

Author: rkennke

src/hotspot/share/gc/shenandoah/shenandoahBarrierSet.inline.hpp

@@ -113,7 +113,6 @@ inline oop ShenandoahBarrierSet::load_reference_barrier(oop obj, T* load_addr) {
   if ((HasDecorator<decorators, ON_WEAK_OOP_REF>::value || HasDecorator<decorators, ON_UNKNOWN_OOP_REF>::value) &&
       obj != NULL && _heap->is_concurrent_weak_root_in_progress() &&
       !_heap->marking_context()->is_marked_strong(obj)) {
-    assert(Thread::current()->is_Java_thread(), "only Java threads get here");
     return NULL;
   }