v2: Explicitly use GL_NO_ERROR instead of expected_error in the
'piglit_is_extension_supported("GL_NV_fog_distance") &&
!piglit_is_extension_supported("GL_SGIS_fog_function")' block.  Based on
conversation with Eric.

v3: Add some missing newlines in printfs.  This caused the CI to show
"Incomplete run" instead of pass.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>