Skip bad cwd test on anything but Linux
Skip bad cwd test on anything but Linux

By suggestion from doughera++. Should fix TT #1951.

tkob/parrot,gitster/parrot,youprofit/parrot,gagern/parrot,gitster/parrot,parrot/parrot,tkob/parrot,FROGGS/parrot,FROGGS/parrot,youprofit/parrot,parrot/parrot,youprofit/parrot,gitster/parrot,gitster/parrot,FROGGS/parrot,tkob/parrot,gagern/parrot,gagern/parrot,parrot/parrot,youprofit/parrot,youprofit/parrot,tkob/parrot,FROGGS/parrot,tkob/parrot,FROGGS/parrot,FROGGS/parrot,gagern/parrot,gagern/parrot,gagern/parrot,gitster/parrot,FROGGS/parrot,gitster/parrot,youprofit/parrot,gagern/parrot,tkob/parrot,tkob/parrot,parrot/parrot,FROGGS/parrot,tkob/parrot,youprofit/parrot,parrot/parrot,gitster/parrot,youprofit/parrot