netfilter: nf_conntrack_extend: avoid unnecessary "ct->ext" dereferences

As Linus points out, "ct->ext" and "new" are always equal, avoid unnecessary
dereferences and use "new" directly.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/netfilter/nf_conntrack_extend.c

@@ -115,10 +115,10 @@ void *__nf_ct_ext_add(struct nf_conn *ct, enum nf_ct_ext_id id, gfp_t gfp)
 		ct->ext = new;
 	}
 
-	ct->ext->offset[id] = newoff;
-	ct->ext->len = newlen;
-	memset((void *)ct->ext + newoff, 0, newlen - newoff);
-	return (void *)ct->ext + newoff;
+	new->offset[id] = newoff;
+	new->len = newlen;
+	memset((void *)new + newoff, 0, newlen - newoff);
+	return (void *)new + newoff;
 }
 EXPORT_SYMBOL(__nf_ct_ext_add);