Expand the various pkcs11 config paths properly.
Expand the various pkcs11 config paths properly.

 * Without this the ${prefix} part of the variable wasn't being
   expanded and was making it into the #define.

Distrotech/p11-kit,pspacek/p11-kit,Distrotech/p11-kit,freedesktop-unofficial-mirror/p11-glue__p11-kit,pspacek/p11-kit,lkundrak/p11-kit,lkundrak/p11-kit,pspacek/p11-kit,freedesktop-unofficial-mirror/p11-glue__p11-kit,pspacek/p11-kit,lkundrak/p11-kit,Distrotech/p11-kit,Distrotech/p11-kit,freedesktop-unofficial-mirror/p11-glue__p11-kit