[Kotlin] Fix methods that return containers

The returnAllocation logic was not wired up to the args struct.

I was also able to simplify the logic in the second call parameter loop.

Bug: 375591466
Test: FeaturesTest
Change-Id: I4da704dfec427fc96b0915fca4dd57c3d74cfcca
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/212414
Reviewed-by: Corentin Wallez <[email protected]>
Auto-Submit: Jim Blackler <[email protected]>
Commit-Queue: Jim Blackler <[email protected]>

Author: jimblacklercorp

generator/templates/art/methods.cpp

@@ -126,15 +126,14 @@ jobject toByteBuffer(JNIEnv *env, const void* address, jlong size) {
             {% endfor %}
         );
         //* Allocate the native container
-        auto returnAllocation = std::make_unique<{{ as_cType(_kotlin_return.type.name) }}[]>(size);
+        args.{{ as_varName(_kotlin_return.name) }} = c.AllocArray<{{ as_cType(_kotlin_return.type.name) }}>(size);
         if (env->ExceptionCheck()) {  //* Early out if client (Kotlin) callback threw an exception.
             return nullptr;
         }
         //* Second call completes the native container
         wgpu{{ object.name.CamelCase() }}{{ method.name.CamelCase() }}(handle
             {% for arg in method.arguments -%}
-                {{- ', ' if object or not loop.first -}}
-                {{- 'returnAllocation.get()' if arg == _kotlin_return else "args." + as_varName(arg.name) -}}
+               , {{- "args." + as_varName(arg.name) -}}
             {% endfor %}
         );
         if (env->ExceptionCheck()) {  //* Early out if client (Kotlin) callback threw an exception.