esp: remove redundant define esph

The pointer 'esph' is defined but is never used hence it is redundant
and canbe removed.

Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index 9768901..211caaf 100644
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -683,12 +683,11 @@ static void esp_input_done_esn(struct crypto_async_request *base, int err)
  */
 static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
 {
-	struct ip_esp_hdr *esph;
 	struct crypto_aead *aead = x->data;
 	struct aead_request *req;
 	struct sk_buff *trailer;
 	int ivlen = crypto_aead_ivsize(aead);
-	int elen = skb->len - sizeof(*esph) - ivlen;
+	int elen = skb->len - sizeof(struct ip_esp_hdr) - ivlen;
 	int nfrags;
 	int assoclen;
 	int seqhilen;
@@ -698,13 +697,13 @@ static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
 	struct scatterlist *sg;
 	int err = -EINVAL;
 
-	if (!pskb_may_pull(skb, sizeof(*esph) + ivlen))
+	if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + ivlen))
 		goto out;
 
 	if (elen <= 0)
 		goto out;
 
-	assoclen = sizeof(*esph);
+	assoclen = sizeof(struct ip_esp_hdr);
 	seqhilen = 0;
 
 	if (x->props.flags & XFRM_STATE_ESN) {