nouveau: typecast the prime_fd handle when calling nouveau_bo_set_prime

Core drm defines that the handle is of type int, while all drivers
treat it as uint internally. Typecast the value to silence gcc
warning messages and be consistent amongst all drivers.

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>

src/gallium/drivers/nouveau/nouveau_screen.c

@@ -123,7 +123,7 @@ nouveau_screen_bo_get_handle(struct pipe_screen *pscreen,
 		whandle->handle = bo->handle;
 		return TRUE;
 	} else if (whandle->type == DRM_API_HANDLE_TYPE_FD) {
-		return nouveau_bo_set_prime(bo, &whandle->handle) == 0;
+		return nouveau_bo_set_prime(bo, (int *)&whandle->handle) == 0;
 	} else {
 		return FALSE;
 	}