crash in virQEMUCapsProbeQMPTPM

[Peter Krempa]

On Mon, Jul 05, 2021 at 00:15:56 +0200, Olaf Hering wrote:
> I got a couple of "g_strv_contains: assertion 'strv != NULL' failed" in the past days.
> 
> It seems qemuMonitorGetTPMModels can write NULL into "models" in "virQEMUCapsProbeQMPTPM()".
> As a result g_strv_contains will crash with G_DEBUG=fatal-warnings
> This is libvirt.git#15073504db and qemu.git#13d5f87cc3

That is probably a bug caused by oversight in my refactors. I'll fix
it soon hopefully