Init fresnel_weight in sss tests.
Init fresnel_weight in sss tests.

aiivashchenko/appleseed,aytekaman/appleseed,luisbarrancos/appleseed,pjessesco/appleseed,appleseedhq/appleseed,dictoon/appleseed,gospodnetic/appleseed,Vertexwahn/appleseed,dictoon/appleseed,aiivashchenko/appleseed,aytekaman/appleseed,gospodnetic/appleseed,Biart95/appleseed,pjessesco/appleseed,Aakash1312/appleseed,dictoon/appleseed,luisbarrancos/appleseed,Biart95/appleseed,Vertexwahn/appleseed,appleseedhq/appleseed,pjessesco/appleseed,glebmish/appleseed,est77/appleseed,glebmish/appleseed,Aakash1312/appleseed,aytekaman/appleseed,dictoon/appleseed,gospodnetic/appleseed,glebmish/appleseed,luisbarrancos/appleseed,appleseedhq/appleseed,dictoon/appleseed,Aakash1312/appleseed,glebmish/appleseed,luisbarrancos/appleseed,est77/appleseed,pjessesco/appleseed,Vertexwahn/appleseed,glebmish/appleseed,luisbarrancos/appleseed,appleseedhq/appleseed,gospodnetic/appleseed,aytekaman/appleseed,Vertexwahn/appleseed,aiivashchenko/appleseed,appleseedhq/appleseed,gospodnetic/appleseed,Aakash1312/appleseed,Biart95/appleseed,est77/appleseed,pjessesco/appleseed,Vertexwahn/appleseed,Biart95/appleseed,aiivashchenko/appleseed,aytekaman/appleseed,est77/appleseed,est77/appleseed,Biart95/appleseed,aiivashchenko/appleseed,Aakash1312/appleseed