qemu: Invalidate capabilities when host CPU changes

The host CPU related info stored in the capabilities cache is no longer
valid after the host CPU changes. This is not a frequent situation in
real world, but it can easily happen in nested scenarios when a disk
image is started with various CPUs.

https://bugzilla.redhat.com/show_bug.cgi?id=1778819

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

tests/qemucapsprobe.c

@@ -77,7 +77,7 @@ main(int argc, char **argv)
         return EXIT_FAILURE;
 
     if (!(caps = virQEMUCapsNewForBinaryInternal(VIR_ARCH_NONE, argv[1], "/tmp",
-                                                 -1, -1, 0, NULL)))
+                                                 -1, -1, NULL, 0, NULL)))
         return EXIT_FAILURE;
 
     virObjectUnref(caps);