Use $$clean_path

Seems more robust than a regexp, and the right thing to use in this case.

Change-Id: I1ca320606c50fb3d5f593025e23b3e08ae77a124
Reviewed-by: Jocelyn Turcotte <jocelyn.turcotte@digia.com>
Gratuitous .prf cleanup

Change-Id: I6b4d1ec92b3adc2145a1f2aeec7038eac079d4e8
Reviewed-by: Andras Becsi <andras.becsi@digia.com>