orcmips: Fix register range check
orcmips: Fix register range check

There are 32 possible registers and not 33

CID #1146987

jpakkane/orc,jpakkane/orc,ijsf/OpenWebRTC-orc,jpakkane/orc,ijsf/OpenWebRTC-orc,mojaves/orc,mojaves/orc,ijsf/OpenWebRTC-orc,mojaves/orc