ivshmem: Mark questionable socket type test FIXME

Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NMarc-André Lureau <marcandre.lureau@redhat.com>

hw/misc/ivshmem.c

@@ -939,6 +939,7 @@ static void pci_ivshmem_realize(PCIDevice *dev, Error **errp)
         memory_region_add_subregion(&s->bar, 0, mr);
         pci_register_bar(PCI_DEVICE(s), 2, attr, &s->bar);
     } else if (s->server_chr != NULL) {
+        /* FIXME do not rely on what chr drivers put into filename */
         if (strncmp(s->server_chr->filename, "unix:", 5)) {
             error_setg(errp, "chardev is not a unix client socket");
             return;