conf: Refactor control flow in virDomainDiskBackingStoreParse
conf: Refactor control flow in virDomainDiskBackingStoreParse

The function does not have any code in the 'cleanup' label so we can
simplify the control flow.

Signed-off-by: Peter Krempa <2cf5c04c61aa466e4a47bfedc747d17279c72ffc@redhat.com>
Reviewed-by: Ján Tomko <4cab11cfb98d3c937327354a78eb07dbb6ee2bc6@redhat.com>

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