fix ValueError message in LlamaAttention (#22966)

src/transformers/models/llama/modeling_llama.py

@@ -216,7 +216,7 @@ class LlamaAttention(nn.Module):
 
         if attn_weights.size() != (bsz, self.num_heads, q_len, kv_seq_len):
             raise ValueError(
-                f"Attention weights should be of size {(bsz * self.num_heads, q_len, kv_seq_len)}, but is"
+                f"Attention weights should be of size {(bsz, self.num_heads, q_len, kv_seq_len)}, but is"
                 f" {attn_weights.size()}"
             )