fix another m44 bug in debugger

Change-Id: Id80344a71b54c80609ec24947014592d6b30eb63
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/341001
Reviewed-by: Kevin Lubick <kjlubick@google.com>
Commit-Queue: Nathaniel Nifong <nifong@google.com>
1 file changed