modify according to comment

src/xrpld/app/tx/detail/AMMClawback.cpp

@@ -42,6 +42,10 @@ AMMClawback::preflight(PreflightContext const& ctx)
     if (auto const ret = preflight1(ctx); !isTesSuccess(ret))
         return ret;  // LCOV_EXCL_LINE
 
+    auto const flags = ctx.tx.getFlags();
+    if (flags & tfAMMClawbackMask)
+        return temINVALID_FLAG;
+
     AccountID const issuer = ctx.tx[sfAccount];
     AccountID const holder = ctx.tx[sfHolder];
 
@@ -53,22 +57,18 @@ AMMClawback::preflight(PreflightContext const& ctx)
     }
 
     std::optional<STAmount> const clawAmount = ctx.tx[~sfAmount];
-    auto const& asset = ctx.tx[sfAsset];
-    auto const& asset2 = ctx.tx[sfAsset2];
-    auto const& flags = ctx.tx.getFlags();
+    auto const asset = ctx.tx[sfAsset];
+    auto const asset2 = ctx.tx[sfAsset2];
 
     if (isXRP(asset))
         return temMALFORMED;
 
-    if (flags & tfAMMClawbackMask)
-        return temINVALID_FLAG;
-
     if (flags & tfClawTwoAssets && asset.account != asset2.account)
     {
         JLOG(ctx.j.trace())
             << "AMMClawback: tfClawTwoAssets can only be enabled when two "
                "assets in the AMM pool are both issued by the issuer";
-        return temINVALID_FLAG;
+        return temMALFORMED;
     }
 
     if (asset.account != issuer)