tcg/optimize: Use finish_folding in fold_dup, fold_dup2

Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
diff --git a/tcg/optimize.c b/tcg/optimize.c
index a68221a..803bceb 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -1698,7 +1698,7 @@
         t = dup_const(TCGOP_VECE(op), t);
         return tcg_opt_gen_movi(ctx, op, op->args[0], t);
     }
-    return false;
+    return finish_folding(ctx, op);
 }
 
 static bool fold_dup2(OptContext *ctx, TCGOp *op)
@@ -1713,7 +1713,7 @@
         op->opc = INDEX_op_dup_vec;
         TCGOP_VECE(op) = MO_32;
     }
-    return false;
+    return finish_folding(ctx, op);
 }
 
 static bool fold_eqv(OptContext *ctx, TCGOp *op)