util: better handle program names from wine

For some reason wine will sometimes give us a windows style path
for an application. For example when running the 64bit version
of Rage wine gives a Unix style path, but when running the 32bit
version is gives a windows style path.

If we detect no '/' in the path at all it should be safe to
assume we have a wine application and instead look for a '\'.

Reviewed-by: Eric Engestrom <eric.engestrom@intel.com>
(cherry picked from commit 3f9d8e9c)