Remove unnecessary diagnum argument in mj_solveLD and mj_factorI

PiperOrigin-RevId: 758669364
Change-Id: Icfefc4a7a1e7d28da373725358ccf9d5f589f689

src/engine/engine_solver.c

@@ -1071,7 +1071,7 @@ static void CGupdateGradient(mjCGContext* ctx, int flg_Newton) {
   else {
     mju_copy(ctx->Mgrad, ctx->grad, nv);
     mj_solveLD(ctx->Mgrad, ctx->qLD, ctx->qLDiagInv, nv, 1,
-               ctx->M_rownnz, ctx->M_rowadr, ctx->M_diagnum, ctx->M_colind);
+               ctx->M_rownnz, ctx->M_rowadr, ctx->M_colind);
   }
 }