[D3D] Z buffer fix

[Christian Costa <titan.costa@wanadoo.fr>]

Hi,

Some games only ask for 16 bits Z buffer even if we support higher depth.
This patch make them happy. The Mechwarrior 3 demo recognizes our D3D 
driver now.

Bye,
Christian.

Changelog :
Add support for all Z buffer depths that are lower that the current one.

Christian Costa   titan.costa@wanadoo.fr

Index: mesa.c
===================================================================
RCS file: /home/wine/wine/dlls/ddraw/d3ddevice/mesa.c,v
retrieving revision 1.141
diff -u -r1.141 mesa.c
--- mesa.c	6 Oct 2003 21:03:32 -0000	1.141
+++ mesa.c	15 Oct 2003 19:31:42 -0000
@@ -4010,9 +4010,9 @@
     TRACE(": Z bits = %d\n", depth_bits);
     switch (depth_bits) {
         case 16: opengl_device_caps.dwDeviceZBufferBitDepth = DDBD_16; break;
-        case 24: opengl_device_caps.dwDeviceZBufferBitDepth = DDBD_24; break;
-	case 32: opengl_device_caps.dwDeviceZBufferBitDepth = DDBD_32; break;
-	default: opengl_device_caps.dwDeviceZBufferBitDepth = DDBD_16|DDBD_24|DDBD_32; break;
+        case 24: opengl_device_caps.dwDeviceZBufferBitDepth = DDBD_16|DDBD_24; break;
+        case 32:
+        default: opengl_device_caps.dwDeviceZBufferBitDepth = DDBD_16|DDBD_24|DDBD_32; break;
     }
 }