minor change

Author: Jianhui-Li

mlir/test/lib/Dialect/XeGPU/TestXeGPUTransforms.cpp

@@ -107,7 +107,7 @@ struct TestXeGPUUnrollingPatterns
             // If the encoding is a ScatterTensorDescAttr, we need to
             // potentially adjust the chunk size based on the inst_data.
             if (tdescTy.isScattered()) {
-              auto scatterAttr = tdescTy.getEncodingAsScatterTensorDescAttr();
+              auto scatterAttr = llvm::dyn_cast_if_present<xegpu::ScatterTensorDescAttr>(encoding);        
               int64_t chunkSize = scatterAttr.getChunkSize().getInt();
 
               if (chunkSize > 1) {