improves LoanManage error code for dust amounts

Author: Tapanito

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

@@ -223,11 +223,11 @@ LoanManage::defaultLoan(
         }
         if (*vaultAvailableProxy > *vaultTotalProxy)
         {
-            JLOG(j.warn()) << "Vault assets available must not be greater "
-                              "than assets outstanding. Available: "
-                           << *vaultAvailableProxy
-                           << ", Total: " << *vaultTotalProxy;
-            return tecLIMIT_EXCEEDED;
+            JLOG(j_.fatal())
+                << "Vault assets available must not be greater "
+                   "than assets outstanding. Available: "
+                << *vaultAvailableProxy << ", Total: " << *vaultTotalProxy;
+            return tecINTERNAL;  // LCOV_EXCL_LINE
         }
 
         // The loss has been realized

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

@@ -454,9 +454,11 @@ LoanPay::doApply()
 
         if (*assetsAvailableProxy > *assetsTotalProxy)
         {
-            // LCOV_EXCL_START
-            return tecINTERNAL;
-            // LCOV_EXCL_STOP
+            JLOG(j_.fatal())
+                << "Vault assets available must not be greater "
+                   "than assets outstanding. Available: "
+                << *assetsAvailableProxy << ", Total: " << *assetsTotalProxy;
+            return tecINTERNAL;  // LCOV_EXCL_LINE
         }
     }