fix test

Author: tkarna

mlir/test/Dialect/XeGPU/transform-ops-invalid.mlir

@@ -61,7 +61,7 @@ func.func @set_gpu_launch_threads_bad_threads(%arg0: memref<4096x4096xf16>) {
 module attributes {transform.with_named_sequence} {
   transform.named_sequence @__transform_main(%arg1: !transform.any_op {transform.readonly}) {
     %0 = transform.structured.match ops{["gpu.launch"]} in %arg1 : (!transform.any_op) -> !transform.any_op
-    // expected-error@below {{Expected threads to be a 3D vector}}
+    // expected-error@below {{Expected threads argument to consist of three values (got 2)}}
     transform.xegpu.set_gpu_launch_threads %0 threads = [8, 4] : !transform.any_op
     transform.yield
   }