panfrost: Fix pan_blitter_emit_bifrost_blend()

If we return inside a pan_pack() the descriptor packing doesn't happen.

Cc: mesa-stable
Fixes: 8ba2f9f698 ("panfrost: Create a blitter library to replace the existing preload helpers")
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/12239>

src/panfrost/lib/pan_blitter.c

@@ -228,7 +228,7 @@ pan_blitter_emit_bifrost_blend(const struct panfrost_device *dev,
                 if (!iview) {
                         cfg.enable = false;
                         cfg.bifrost.internal.mode = MALI_BIFROST_BLEND_MODE_OFF;
-                        return;
+                        continue;
                 }
 
                 nir_alu_type type = blit_shader->key.surfaces[rt].type;