pipe-loader: directly use pipe_loader_sw_probe_null() at probe time

Due to the nature of the other sw winsys' we cannot use them during the
generic probe stage. As such there is little point in keeping the
abstraction layer.

Cc: Tom Stellard <thomas.stellard@amd.com>
Cc: Francisco Jerez <currojerez@riseup.net>
Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Acked-by: Rob Clark <robclark@freedesktop.org>

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

@@ -46,10 +46,6 @@ struct pipe_loader_sw_device {
 
 static struct pipe_loader_ops pipe_loader_sw_ops;
 
-static struct sw_winsys *(*backends[])() = {
-   null_sw_create
-};
-
 static bool
 pipe_loader_sw_probe_init_common(struct pipe_loader_sw_device *sdev)
 {
@@ -124,16 +120,11 @@ pipe_loader_sw_probe_null(struct pipe_loader_device **devs)
 int
 pipe_loader_sw_probe(struct pipe_loader_device **devs, int ndev)
 {
-   int i;
-
-   for (i = 0; i < Elements(backends); i++) {
-      if (i < ndev) {
-         struct pipe_loader_sw_device *sdev = CALLOC_STRUCT(pipe_loader_sw_device);
-	 /* TODO: handle CALLOC_STRUCT failure */
+   int i = 1;
 
-         sdev->ws = backends[i]();
-         pipe_loader_sw_probe_init_common(sdev);
-         devs[i] = &sdev->base;
+   if (i < ndev) {
+      if (!pipe_loader_sw_probe_null(devs)) {
+         i--;
       }
    }