tools: virsh-snapshot: refactor small functions
tools: virsh-snapshot: refactor small functions

This patch includes:
* removal of dead code
* simplifying nested if conditions
* removal of unnecessary variables
* usage of "direct" boolean return

Signed-off-by: Kristina Hanicova <e70d889c982bbe3b9ce2841af457ca911bff1baa@redhat.com>
Signed-off-by: Michal Privoznik <83d82aaba2eed257f4814b0c239c260c4caaadf0@redhat.com>
Reviewed-by: Michal Privoznik <83d82aaba2eed257f4814b0c239c260c4caaadf0@redhat.com>

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