vbox: vboxDumpAudio: invert conditions
vbox: vboxDumpAudio: invert conditions

Elimination of the positive conditions reduces
the indentation by two levels.

Signed-off-by: Ján Tomko <4cab11cfb98d3c937327354a78eb07dbb6ee2bc6@redhat.com>
Reviewed-by: Erik Skultety <2c14d38fa47c8799f1b9c16280abe27f8edfec6e@redhat.com>

jfehlig/libvirt,jfehlig/libvirt,jfehlig/libvirt,crobinso/libvirt,crobinso/libvirt,libvirt/libvirt,jardasgit/libvirt,crobinso/libvirt,libvirt/libvirt,libvirt/libvirt,zippy2/libvirt,jfehlig/libvirt,jardasgit/libvirt,nertpinx/libvirt,nertpinx/libvirt,jardasgit/libvirt,olafhering/libvirt,olafhering/libvirt,crobinso/libvirt,jardasgit/libvirt,jardasgit/libvirt,zippy2/libvirt,olafhering/libvirt,zippy2/libvirt,zippy2/libvirt,libvirt/libvirt,nertpinx/libvirt,nertpinx/libvirt,olafhering/libvirt,nertpinx/libvirt