Fix string of post decrement in cc1
Fix string of post decrement in cc1

it had ;= instead of ;- that it is the correct value.

8l/scc,k0gaMSX/kcc,k0gaMSX/scc,k0gaMSX/scc,8l/scc,k0gaMSX/kcc,k0gaMSX/scc,8l/scc