netfilter: ip6tables: Remove redundant null checks

Remove superfluous check for NULL pointer to header.
Signed-off-by: Gaurav Singh <gaurav1086@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/ipv6/netfilter/ip6t_ah.c

@@ -74,8 +74,7 @@ static bool ah_mt6(const struct sk_buff *skb, struct xt_action_param *par)
 		 ahinfo->hdrres, ah->reserved,
 		 !(ahinfo->hdrres && ah->reserved));
 
-	return (ah != NULL) &&
-		spi_match(ahinfo->spis[0], ahinfo->spis[1],
+	return spi_match(ahinfo->spis[0], ahinfo->spis[1],
 			  ntohl(ah->spi),
 			  !!(ahinfo->invflags & IP6T_AH_INV_SPI)) &&
 		(!ahinfo->hdrlen ||

net/ipv6/netfilter/ip6t_frag.c

@@ -85,8 +85,7 @@ frag_mt6(const struct sk_buff *skb, struct xt_action_param *par)
 		 !((fraginfo->flags & IP6T_FRAG_NMF) &&
 		   (ntohs(fh->frag_off) & IP6_MF)));
 
-	return (fh != NULL) &&
-		id_match(fraginfo->ids[0], fraginfo->ids[1],
+	return id_match(fraginfo->ids[0], fraginfo->ids[1],
 			 ntohl(fh->identification),
 			 !!(fraginfo->invflags & IP6T_FRAG_INV_IDS)) &&
 		!((fraginfo->flags & IP6T_FRAG_RES) &&

net/ipv6/netfilter/ip6t_hbh.c

@@ -86,8 +86,7 @@ hbh_mt6(const struct sk_buff *skb, struct xt_action_param *par)
 		  ((optinfo->hdrlen == hdrlen) ^
 		   !!(optinfo->invflags & IP6T_OPTS_INV_LEN))));
 
-	ret = (oh != NULL) &&
-	      (!(optinfo->flags & IP6T_OPTS_LEN) ||
+	ret = (!(optinfo->flags & IP6T_OPTS_LEN) ||
 	       ((optinfo->hdrlen == hdrlen) ^
 		!!(optinfo->invflags & IP6T_OPTS_INV_LEN)));
 

net/ipv6/netfilter/ip6t_rt.c

@@ -89,8 +89,7 @@ static bool rt_mt6(const struct sk_buff *skb, struct xt_action_param *par)
 		 !((rtinfo->flags & IP6T_RT_RES) &&
 		   (((const struct rt0_hdr *)rh)->reserved)));
 
-	ret = (rh != NULL) &&
-	      (segsleft_match(rtinfo->segsleft[0], rtinfo->segsleft[1],
+	ret = (segsleft_match(rtinfo->segsleft[0], rtinfo->segsleft[1],
 			      rh->segments_left,
 			      !!(rtinfo->invflags & IP6T_RT_INV_SGS))) &&
 	      (!(rtinfo->flags & IP6T_RT_LEN) ||