!7064 fix build java error

Merge pull request !7064 from yeyunpeng2020/java_fix

build.sh

@@ -304,6 +304,7 @@ checkopts()
           LITE_LANGUAGE="cpp"
         elif [[ "$OPTARG" == "java" ]]; then
           LITE_LANGUAGE="java"
+	  ENABLE_CONVERTER="off"
         elif [[ "$OPTARG" == "object-c" ]]; then
           LITE_LANGUAGE="object-c"
         else

mindspore/lite/src/kernel_registry.cc

@@ -116,8 +116,11 @@ kernel::LiteKernel *KernelRegistry::GetKernel(const std::vector<Tensor *> &in_te
   auto creator = GetCreator(key);
   if (creator != nullptr) {
     auto kernel = creator(in_tensors, out_tensors, parameter, ctx, key, primitive);
-    return kernel;
+    if (kernel != nullptr) {
+      return kernel;
+    }
   }
+  free(parameter);
   return nullptr;
 }