spirv: Fix OpCopyMemorySized

I have no idea how we are passing CTS tests with that bug in there.  I
guess by luck?

Fixes: 8323c03bbfd45 "spirv: Add support for OpCopyMemorySized"
Reviewed-by: Jesse Natalie <jenatali@microsoft.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7294>
1 file changed