fix MTRDevice_Concrete block-scoped pointer types

Author: kiel-apple

src/darwin/Framework/CHIP/MTRDevice_Concrete.mm

@@ -2873,7 +2873,7 @@ static BOOL AttributeHasChangesOmittedQuality(MTRAttributePath * attributePath)
             }
             *stop = NO;
         }];
-        [workItem setReadyHandler:^(MTRDevice * self, NSInteger retryCount, MTRAsyncWorkCompletionBlock completion) {
+        [workItem setReadyHandler:^(MTRDevice_Concrete * self, NSInteger retryCount, MTRAsyncWorkCompletionBlock completion) {
             // Sanity check
             if (readRequests.count == 0) {
                 MTR_LOG_ERROR("Read attribute work item [%llu] contained no read requests", workItemID);
@@ -3014,7 +3014,7 @@ - (void)writeAttributeWithEndpointID:(NSNumber *)endpointID
         *isDuplicate = NO;
         *stop = YES;
     }];
-    [workItem setReadyHandler:^(MTRDevice * self, NSInteger retryCount, MTRAsyncWorkCompletionBlock completion) {
+    [workItem setReadyHandler:^(MTRDevice_Concrete * self, NSInteger retryCount, MTRAsyncWorkCompletionBlock completion) {
         MTRBaseDevice * baseDevice = [self newBaseDevice];
         // Make sure to use writeRequests here, because that's what our batching
         // handler will modify as needed.
@@ -3148,7 +3148,7 @@ - (void)_invokeCommandWithEndpointID:(NSNumber *)endpointID
         *isDuplicate = NO;
         *stop = YES;
     }];
-    [workItem setReadyHandler:^(MTRDevice * self, NSInteger retryCount, MTRAsyncWorkCompletionBlock workCompletion) {
+    [workItem setReadyHandler:^(MTRDevice_Concrete * self, NSInteger retryCount, MTRAsyncWorkCompletionBlock workCompletion) {
         auto workDone = ^(NSArray<NSDictionary<NSString *, id> *> * _Nullable values, NSError * _Nullable error) {
             dispatch_async(queue, ^{
                 completion(values, error);