nak: Use nak_builder::fsetp() in op_fquantize2f16

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30448>

src/nouveau/compiler/nak/from_nir.rs

@@ -1163,15 +1163,11 @@ impl<'a> ShaderFromNir<'a> {
                 if b.sm() < 70 {
                     // Pre-Volta, F2F.ftz doesn't flush denorms so we need to do
                     // that manually
-                    let denorm = b.alloc_ssa(RegFile::Pred, 1);
-                    b.push_op(OpFSetP {
-                        dst: denorm.into(),
-                        set_op: PredSetOp::And,
-                        cmp_op: FloatCmpOp::OrdLt,
-                        srcs: [srcs[0].fabs(), 0x38800000.into()],
-                        accum: true.into(),
-                        ftz: false,
-                    });
+                    let denorm = b.fsetp(
+                        FloatCmpOp::OrdLt,
+                        srcs[0].fabs(),
+                        0x38800000.into(),
+                    );
                     // Get the correctly signed zero
                     let zero =
                         b.lop2(LogicOp2::And, srcs[0], 0x80000000.into());