tests: add a function for checking exclusive flags
tests: add a function for checking exclusive flags

We can reject some non-sensical combinations with an error
message, once we add flags for them.

Signed-off-by: Ján Tomko <4cab11cfb98d3c937327354a78eb07dbb6ee2bc6@redhat.com>

jfehlig/libvirt,nertpinx/libvirt,crobinso/libvirt,zippy2/libvirt,nertpinx/libvirt,eskultety/libvirt,libvirt/libvirt,zippy2/libvirt,eskultety/libvirt,jardasgit/libvirt,crobinso/libvirt,zippy2/libvirt,zippy2/libvirt,fabianfreyer/libvirt,crobinso/libvirt,andreabolognani/libvirt,andreabolognani/libvirt,nertpinx/libvirt,olafhering/libvirt,fabianfreyer/libvirt,jardasgit/libvirt,jfehlig/libvirt,andreabolognani/libvirt,nertpinx/libvirt,eskultety/libvirt,libvirt/libvirt,jardasgit/libvirt,olafhering/libvirt,fabianfreyer/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,libvirt/libvirt,olafhering/libvirt,olafhering/libvirt,eskultety/libvirt,andreabolognani/libvirt,eskultety/libvirt,jardasgit/libvirt,jardasgit/libvirt,fabianfreyer/libvirt,crobinso/libvirt,andreabolognani/libvirt,jfehlig/libvirt,libvirt/libvirt,jfehlig/libvirt