[example48] fix begin flag bug + small change

Author: Erfan-Ahmadi

examples_tests/48.ArithmeticUnitTest/main.cpp

@@ -247,7 +247,7 @@ bool runTest(
 {
 	// TODO: overlap dispatches with memory readbacks (requires multiple copies of `buffers`)
 
-	cmdbuf->begin(IGPUCommandBuffer::ERF_RELEASE_RESOURCES_BIT);
+	cmdbuf->begin(IGPUCommandBuffer::EU_NONE);
 	cmdbuf->bindComputePipeline(pipeline);
 	cmdbuf->bindDescriptorSets(asset::EPBP_COMPUTE,pipeline->getLayout(),0u,1u,&ds);
 	const uint32_t workgroupCount = BUFFER_DWORD_COUNT/workgroupSize;
@@ -305,7 +305,7 @@ class ArythmeticUnitTestApp : public NonGraphicalApplicationBase
 	void onAppInitialized_impl() override
 	{
 		CommonAPI::InitOutput initOutput;
-		CommonAPI::InitWithNoExt(initOutput, video::EAT_VULKAN, "Subgroup Arithmetic Test");
+		CommonAPI::InitWithNoExt(initOutput, video::EAT_OPENGL, "Subgroup Arithmetic Test");
 		gl = std::move(initOutput.apiConnection);
 		gpuPhysicalDevice = std::move(initOutput.physicalDevice);
 		logicalDevice = std::move(initOutput.logicalDevice);
@@ -380,6 +380,7 @@ class ArythmeticUnitTestApp : public NonGraphicalApplicationBase
 			assert(mreq.memoryTypeBits);
 			// (Erfan to Cyprian) We usually don't use the return value (SMemoryOffset) of the allocate function but make sure you set it to some variable named bufferMem or something so we know it's there
 			auto bufferMem = logicalDevice->allocate(mreq, buffers[i].get());
+			assert(bufferMem.isValid())
 
 			IDeviceMemoryAllocation::MappedMemoryRange mem;
 			mem.memory = buffers[i]->getBoundMemory();