qemu: change first arg of qemuDomainAttachChrDeviceAssignAddr()

from virDomainDefPtr to virDomainObjPtr so that the function has
access to the other parts of the virDomainObjPtr. Take advantage of
this by removing the "priv" arg and retrieving it from the
virDomainObjPtr instead.

No functional change.

src/qemu/qemu_hotplug.c

@@ -1636,10 +1636,11 @@ qemuDomainChrRemove(virDomainDefPtr vmdef,
 }
 
 static int
-qemuDomainAttachChrDeviceAssignAddr(virDomainDefPtr def,
-                                    qemuDomainObjPrivatePtr priv,
+qemuDomainAttachChrDeviceAssignAddr(virDomainObjPtr vm,
                                     virDomainChrDefPtr chr)
 {
+    virDomainDefPtr def = vm->def;
+    qemuDomainObjPrivatePtr priv = vm->privateData;
     int ret = -1;
     virDomainVirtioSerialAddrSetPtr vioaddrs = NULL;
 
@@ -1715,7 +1716,7 @@ int qemuDomainAttachChrDevice(virQEMUDriverPtr driver,
     if (qemuAssignDeviceChrAlias(vmdef, chr, -1) < 0)
         goto cleanup;
 
-    if ((rc = qemuDomainAttachChrDeviceAssignAddr(vm->def, priv, chr)) < 0)
+    if ((rc = qemuDomainAttachChrDeviceAssignAddr(vm, chr)) < 0)
         goto cleanup;
     if (rc == 1)
         need_release = true;