watchdog: 6300esb: add exit function

When the Intel 6300ESB watchdog is hot unplug. The timer allocated
in realize isn't freed thus leaking memory leak. This patch avoid
this through adding the exit function.

Signed-off-by: Li Qiang <liqiang6-s@360.cn>
Message-Id: <583cde9c.3223ed0a.7f0c2.886e@mx.google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

hw/watchdog/wdt_i6300esb.c

@@ -428,6 +428,14 @@ static void i6300esb_realize(PCIDevice *dev, Error **errp)
     /* qemu_register_coalesced_mmio (addr, 0x10); ? */
 }
 
+static void i6300esb_exit(PCIDevice *dev)
+{
+    I6300State *d = WATCHDOG_I6300ESB_DEVICE(dev);
+
+    timer_del(d->timer);
+    timer_free(d->timer);
+}
+
 static WatchdogTimerModel model = {
     .wdt_name = "i6300esb",
     .wdt_description = "Intel 6300ESB",
@@ -441,6 +449,7 @@ static void i6300esb_class_init(ObjectClass *klass, void *data)
     k->config_read = i6300esb_config_read;
     k->config_write = i6300esb_config_write;
     k->realize = i6300esb_realize;
+    k->exit = i6300esb_exit;
     k->vendor_id = PCI_VENDOR_ID_INTEL;
     k->device_id = PCI_DEVICE_ID_INTEL_ESB_9;
     k->class_id = PCI_CLASS_SYSTEM_OTHER;