Do not use ndash in filenames

Ndashes in filenames will cause problems with some filesystems
and also showed a bug in pbr when running tox.

Note that none of these files was actually used.
There is already a copy without the ndashes in common/figures.

Related-Bug: #1265622

Change-Id: Iff5409daaa8b6e62ab59902e7c47914540a0321c