net: stmmac: Drop redundant skb_mark_for_recycle() for SKB frags

After commit df542f6 ("net: stmmac: Switch to zero-copy in
non-XDP RX path"), SKBs are always marked for recycle, it is redundant
to mark SKBs more than once when new frags are appended.

Signed-off-by: Furong Xu <0x1207@gmail.com>
Link: https://patch.msgid.link/20250117062805.192393-1-0x1207@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

@@ -5644,9 +5644,6 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue)
 			skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
 					buf->page, buf->page_offset, buf1_len,
 					priv->dma_conf.dma_buf_sz);
-
-			/* Data payload appended into SKB */
-			skb_mark_for_recycle(skb);
 			buf->page = NULL;
 		}
 
@@ -5656,9 +5653,6 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue)
 			skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
 					buf->sec_page, 0, buf2_len,
 					priv->dma_conf.dma_buf_sz);
-
-			/* Data payload appended into SKB */
-			skb_mark_for_recycle(skb);
 			buf->sec_page = NULL;
 		}