qemu: migration: Clean up temporary bitmaps when cancelling a migration
qemu: migration: Clean up temporary bitmaps when cancelling a migration

In case when the block migration job required temporary bitmaps for
merging the appropriate checkpoints we need to clean them up when
cancelling the job. On success we don't need to do that though as the
bitmaps are just temporary thus are not written to disk.

Signed-off-by: Peter Krempa <2cf5c04c61aa466e4a47bfedc747d17279c72ffc@redhat.com>
Reviewed-by: Jiri Denemark <62bdf77dc47919a4d59a91822129d14633cfca81@redhat.com>

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