net: xfrm: Fix end of loop tests for list_for_each_entry

stable inclusion
from stable-5.10.61
commit 505884a0c7a1c44e66690b975601220eace0868c
bugzilla: 177029 https://gitee.com/openeuler/kernel/issues/I4EAXD

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=505884a0c7a1c44e66690b975601220eace0868c

--------------------------------

[ Upstream commit 480e93e1 ]

The list_for_each_entry() iterator, "pos" in this code, can never be
NULL so the warning will never be printed.
Signed-off-by: NHarshvardhan Jha <harshvardhan.jha@oracle.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

net/xfrm/xfrm_ipcomp.c

@@ -250,7 +250,7 @@ static void ipcomp_free_tfms(struct crypto_comp * __percpu *tfms)
 			break;
 	}
 
-	WARN_ON(!pos);
+	WARN_ON(list_entry_is_head(pos, &ipcomp_tfms_list, list));
 
 	if (--pos->users)
 		return;