typo & comment

- safe -> save
- commenting code: batch_size, seq_len = in_idx.shape

Author: casinca

ch05/07_gpt_to_llama/converting-gpt-to-llama2.ipynb

@@ -648,7 +648,7 @@
     "\n",
     "mha(example_batch)\n",
     "\n",
-    "del mha  # delete to safe memory"
+    "del mha  # delete to save memory"
    ]
   },
   {
@@ -781,7 +781,7 @@
     "        self.out_head = nn.Linear(cfg[\"emb_dim\"], cfg[\"vocab_size\"], bias=False, dtype=cfg[\"dtype\"])\n",
     "\n",
     "    def forward(self, in_idx):\n",
-    "        batch_size, seq_len = in_idx.shape\n",
+    "        # batch_size, seq_len = in_idx.shape\n",
     "        tok_embeds = self.tok_emb(in_idx)\n",
     "        # pos_embeds = self.pos_emb(torch.arange(seq_len, device=in_idx.device))\n",
     "        x = tok_embeds  # + pos_embeds  # Shape [batch_size, num_tokens, emb_size]\n",