Remove the absolute paths from ironic-deploy-helper.filters

The commands might be located in a different directories on different
distros, so this patch is removing the absolute paths in the
ironic-deploy-helper.filters file.

Change-Id: I68873a04acbf1519165f758b1803f12ba9ddf777
Closes-Bug: #1268696
Merge "Remove the absolute paths from ironic-deploy-helper.filters"