nir: Actually propagate progress in nir_opt_move_load_ubo.

Found with Jasons new metadata rework (mesa/mesa!950).

Fixes: af355aaa "nir: add nir_opt_move_load_ubo() optimization pass"
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Reviewed-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
10 jobs for !975 with move-load-ubo-fix in 8 minutes and 18 seconds (queued for 2 seconds)
detached
Status Job ID Name Coverage
  Containers Build
passed debian #328047

00:00:21

 
  Build+Test
passed meson-clang #328049

00:05:51

passed meson-clover #328053

00:07:57

passed meson-main #328052

00:06:00

passed meson-swr-glvnd #328048

00:04:45

passed meson-vulkan #328054

00:01:38

passed scons-llvm #328056

00:03:15

passed scons-nollvm #328055

00:02:04

passed scons-swr #328050

00:04:57

passed scons-win64 #328051

00:06:35