ii_index terminator allocation leaked on every CCDIOCSET/CCDIOCCLR cycle (ileave>0)

Summary

ccdinterleave ileave>0 path loop body unconditionally kmallocs ii->ii_index at :670 BEFORE testing smallci; when smallci==NULL entry becomes ii_ndisk==0 terminator but ii_index allocation survives. CCDIOCCLR cleanup loop at :1460 stops on ii_ndisk==0 so never frees terminator ii_index. Each configuration cycle with ileave>0 leaks (sizeof(int)*sc_nccdisks) bytes up to 256KB per cycle at CCD_MAXNDISKS. ileave==0 path unaffected (allocates only inside non-terminator loop body).