Kernel: Don't take the thread lock when dispatching signals

This isn't necessary and only leads to deadlocks with SMP.

Author: implicitfield

Kernel/Arch/Processor.cpp

@@ -292,10 +292,8 @@ void ProcessorBase::exit_trap(TrapFrame& trap, bool handling_exception)
             self->smp_process_pending_messages();
 #endif
 
-        if (current_thread) {
-            SpinlockLocker thread_lock(current_thread->get_lock());
+        if (current_thread)
             current_thread->check_dispatch_pending_signal(YieldBehavior::FlagYield);
-        }
 
         // Process the deferred call queue. Among other things, this ensures
         // that any pending thread unblocks happen before we enter the scheduler.