Revert "LivoxGen1: Use syncCancelerForAsyncWork in producer pipeline"

This reverts commit d788810a05.

We're doing this because it's not necessary. We will be porting to
coros soon and we can just use brace-scopes.

stimBuffApis/livoxGen1/ioUringAssemblyEngine.h

@@ -19,7 +19,7 @@
 #include <spinscale/cps/asynchronousContinuation.h>
 #include <spinscale/asynchronousLoop.h>
 #include <spinscale/cps/callback.h>
-#include <spinscale/syncCancelerForAsyncWork.h>
+#include <spinscale/spinLock.h>
 #include <user/frameAssemblyDesc.h>
 #include <user/stagingBuffer.h>
 
@@ -80,7 +80,12 @@ private:
 	boost::asio::deadline_timer stallTimer;
 	// Callback for CQE ntfns (called with user_data+result from each CQE)
 	resetAndAssembleFrameCbFn onCqeReadyCallback;
-	sscl::SyncCancelerForAsyncWork ioUringAssemblyEngnCanceler;
+	/**	EXPLANATION:
+	 * Flag to indicate whether engine should accept new requests.
+	 * Set by setup(), cleared by stop().
+	 */
+	sscl::SpinLock shouldAcceptRequestsLock;
+	bool shouldAcceptRequests;
 
 	size_t nDgramsPerStagingBufferFrame;