drisw: Use debug_screen_wrap like everybody else

I tried to use GALLIUM_TRACE with llvmpipe and it didn't work, because
we were never letting the debug wrappers initialize.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8166>

src/gallium/auxiliary/pipe-loader/pipe_loader_sw.c

@@ -39,10 +39,12 @@
 #include "sw/null/null_sw_winsys.h"
 #include "sw/wrapper/wrapper_sw_winsys.h"
 #include "target-helpers/sw_helper_public.h"
+#include "target-helpers/inline_debug_helper.h"
 #include "frontend/drisw_api.h"
 #include "frontend/sw_driver.h"
 #include "frontend/sw_winsys.h"
 
+
 struct pipe_loader_sw_device {
    struct pipe_loader_device base;
    const struct sw_driver_descriptor *dd;
@@ -316,7 +318,7 @@ pipe_loader_sw_create_screen(struct pipe_loader_device *dev,
    if (!screen)
       sdev->ws->destroy(sdev->ws);
 
-   return screen;
+   return screen ? debug_screen_wrap(screen) : NULL;
 }
 
 static const struct pipe_loader_ops pipe_loader_sw_ops = {

src/gallium/auxiliary/target-helpers/inline_sw_helper.h

@@ -5,6 +5,7 @@
 #include "pipe/p_compiler.h"
 #include "util/u_debug.h"
 #include "frontend/sw_winsys.h"
+#include "target-helpers/inline_debug_helper.h"
 
 #ifdef GALLIUM_SWR
 #include "swr/swr_public.h"
@@ -69,7 +70,7 @@ sw_screen_create_named(struct sw_winsys *winsys, const char *driver)
       screen = d3d12_create_dxcore_screen(winsys, NULL);
 #endif
 
-   return screen;
+   return screen ? debug_screen_wrap(screen) : NULL;
 }