client: fix memory leak in client msg

client: fix memory leak in client msg

When closing client->waitDispatch in virNetClientIOEventLoopRemoveAll
or virNetClientIOEventLoopRemoveDone, VIR_FREE() is called to free
call->msg directly, resulting in leak of the memory call->msg->buffer
points to.
Use virNetMessageFree(call->msg) instead of VIR_FREE(call->msg).

Signed-off-by: Hao Wang <wanghao232@huawei.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>