radeon: With DRI1, if we have HW stencil, only expose fbconfigs with stencil.

Otherwise simple apps like glxgears pick up a DirectColor visual since the X
server mixes the depth 32 visual in with the other GLX visuals, and this seems
to result in a (mostly) black screen due to a bad ColorMap for a lot of people.

The bad ColorMap may be a bug in the apps, the X server or X driver, and
regardless of that I think the X server should ideally make the depth 32 GLX
visual separate from the rest again, but in the meantime this makes us cope.

(depth_bits is either 16 or 24, never 0)
diff --git a/src/mesa/drivers/dri/radeon/radeon_screen.c b/src/mesa/drivers/dri/radeon/radeon_screen.c
index 791f598..a977bed 100644
--- a/src/mesa/drivers/dri/radeon/radeon_screen.c
+++ b/src/mesa/drivers/dri/radeon/radeon_screen.c
@@ -283,12 +283,12 @@
      * with a stencil buffer.  It will be a sw fallback, but some apps won't
      * care about that.
      */
-    stencil_bits_array[0] = 0;
+    stencil_bits_array[0] = stencil_bits;
     stencil_bits_array[1] = (stencil_bits == 0) ? 8 : stencil_bits;
 
     msaa_samples_array[0] = 0;
 
-    depth_buffer_factor = ((depth_bits != 0) || (stencil_bits != 0)) ? 2 : 1;
+    depth_buffer_factor = (stencil_bits == 0) ? 2 : 1;
     back_buffer_factor  = (have_back_buffer) ? 2 : 1;
 
     if (pixel_bits == 16) {