can't find table device while call qemu_input_is_absolute function
Description of problem:
vnc service can‘t run with mouse absolute mode
Steps to reproduce:
1.create a virtual machine with vnc service via virt-manager.

2.delete mouse and table device  if exists.

3.add table devices first,next add mouse device.

4.gdb attach corresponding qemu thread, run command 
print "%d",qemu_input_is_absolute()
display function return false ,so I can't use mouse with absolute mode.
Additional information:
code in  qemu_input_is_absolute() is
```
bool qemu_input_is_absolute(void)
{
    QemuInputHandlerState *s;

    s = qemu_input_find_handler(INPUT_EVENT_MASK_REL | INPUT_EVENT_MASK_ABS,
                                NULL);
    return (s != NULL) && (s->handler->mask & INPUT_EVENT_MASK_ABS);
}
```
qemu_input_find_handler function find a handler INPUT_EVENT_MASK_REL or INPUT_EVENT_MASK_ABS,but just compare with INPUT_EVENT_MASK_ABS,
I think it should be 
```
bool qemu_input_is_absolute(void)
{
    QemuInputHandlerState *s;

    s = qemu_input_find_handler(INPUT_EVENT_MASK_ABS,
                                NULL);
    return (s != NULL) && (s->handler->mask & INPUT_EVENT_MASK_ABS);
}
```
thanks for your help.