llvmpipe: change vendor to be more generic.

If submitting for conformance it is probably better to have a generic
name for vendor here.

Reviewed-by: Roland Scheidegger <sroland@vmware.com>
Reviewed by: Jose Fonseca <jfonseca@vmware.com>

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5483>

src/gallium/drivers/llvmpipe/lp_screen.c

@@ -97,7 +97,7 @@ static const struct debug_named_value lp_perf_flags[] = {
 static const char *
 llvmpipe_get_vendor(struct pipe_screen *screen)
 {
-   return "VMware, Inc.";
+   return "Mesa/X.org";
 }