configuration: fix false failure bug
configuration: fix false failure bug

An inverted condition in an expected-to-fail test case was resulting in
a t.Fatalf(nil) sometimes.  Obviously we shouldn't print a value that
was just verified to be nil.  While I'm at it, I also clarified the
comments around the conditions.

Signed-off-by: Tim Pepper <8dbd764830e941d092a1cb7fa16423169acc0b04@linux.intel.com>

mcastelino/ciao,matthewrsj/ciao,leoswaldo/ciao,tpepper/ciao,erick0z/ciao,wcwxyz/ciao,matthewrsj/ciao,jorgevgut/ciao,ciao-project/ciao,matthewrsj/ciao,wcwxyz/ciao,kaccardi/ciao,erick0z/ciao,rbradford/ciao,tpepper/ciao,tpepper/ciao,01org/ciao,leoswaldo/ciao,mrkz/ciao,erick0z/ciao,mcastelino/ciao,jorgevgut/ciao,rbradford/ciao,mcastelino/ciao,obedmr/ciao,jorgevgut/ciao,ciao-project/ciao,01org/ciao,obedmr/ciao,markdryan/ciao,wcwxyz/ciao,mrkz/ciao,obedmr/ciao,kaccardi/ciao,markdryan/ciao,leoswaldo/ciao,mrkz/ciao