Update examples/attention_sink/example_mha_sink_fwd_bhsd_wgmma_pipelined.py

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

Author: Rachmanino

examples/attention_sink/example_mha_sink_fwd_bhsd_wgmma_pipelined.py

@@ -143,7 +143,7 @@ def main(
             scores_scale = T.alloc_fragment([block_M], accum_dtype)
             scores_sum = T.alloc_fragment([block_M], accum_dtype)
             logsum = T.alloc_fragment([block_M], accum_dtype)
-            sinks = T.alloc_fragment([heads], dtype)
+            sinks = T.alloc_fragment([block_M], dtype)
 
             T.copy(Q[bz, by, bx * block_M:(bx + 1) * block_M, :], Q_shared)
             T.fill(acc_o, 0)