pan/mdg: Fix promoted uniform moves with 64-bit types

The move source is the second src, not the first one.

Fixes: 5e5ea25a0da ("pan/mdg: Explicitly type 64-bit uniform moves")
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8264>
(cherry picked from commit 97929b1aaf4d0bbb9214cd7a31ee938c78f7e8bc)
2 files changed