Don't call lv2_obj::awake_all with empty list

Fixup after #5883

rpcs3/Emu/Cell/lv2/sys_event.cpp

@@ -179,8 +179,11 @@ error_code sys_event_queue_destroy(ppu_thread& ppu, u32 equeue_id, s32 mode)
 				queue->append(cpu);
 			}
 
+			if (!queue->sq.empty())
+			{
 				lv2_obj::awake_all();
 			}
+		}
 		else
 		{
 			for (auto cpu : queue->sq)

rpcs3/Emu/Cell/lv2/sys_event_flag.cpp

@@ -317,9 +317,12 @@ error_code sys_event_flag_set(u32 id, u64 bitptn)
 			return false;
 		});
 
+		if (tail != flag->sq.end())
+		{
 			flag->sq.erase(tail, flag->sq.end());
 			lv2_obj::awake_all();
 		}
+	}
 
 	return CELL_OK;
 }
@@ -380,8 +383,11 @@ error_code sys_event_flag_cancel(ppu_thread& ppu, u32 id, vm::ptr<u32> num)
 			flag->append(thread);
 		}
 
+		if (value)
+		{
 			lv2_obj::awake_all();
 		}
+	}
 
 	if (ppu.test_stopped())
 	{

rpcs3/Emu/Cell/lv2/sys_net.cpp

@@ -206,7 +206,10 @@ extern void network_thread_init()
 				lv2_obj::append(ppu);
 			}
 
+			if (!s_to_awake.empty())
+			{
 				lv2_obj::awake_all();
+			}
 
 			s_to_awake.clear();
 			socklist.clear();

rpcs3/Emu/Cell/lv2/sys_semaphore.cpp

@@ -237,13 +237,18 @@ error_code sys_semaphore_post(ppu_thread& ppu, u32 sem_id, s32 count)
 		}
 
 		// Wake threads
-		for (s32 i = std::min<s32>(-std::min<s32>(val, 0), count); i > 0; i--)
+		const s32 to_awake = std::min<s32>(-std::min<s32>(val, 0), count);
+
+		for (s32 i = 0; i < to_awake; i++)
 		{
 			sem->append(verify(HERE, sem->schedule<ppu_thread>(sem->sq, sem->protocol)));
 		}
 
+		if (to_awake > 0)
+		{
 			lv2_obj::awake_all();
 		}
+	}
 
 	return CELL_OK;
 }