parsing_helpers: remove dead code

Remove three parsers which are not used anywhere in code.  These get_* style
helpers were replaced by parse_* style helpers in the following commit:
455cb40 ("packetXX: Switch parsing helpers to parse_TYPE() style functions").

Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com>

Author: aspsk

common/parsing_helpers.h

@@ -185,77 +185,4 @@ static __always_inline int parse_icmphdr_common(struct hdr_cursor *nh,
 	return h->type;
 }
 
-static __always_inline struct ethhdr *get_ethhdr(struct hdr_cursor *nh,
-						 void *data_end)
-{
-	struct ethhdr *eth = nh->pos;
-	int hdrsize = sizeof(*eth);
-
-	/* Byte-count bounds check; check if current pointer + size of header
-	 * is after data_end.
-	 */
-	if (nh->pos + hdrsize > data_end)
-		return NULL;
-
-	nh->pos += hdrsize;
-	return eth;
-}
-
-static __always_inline struct ipv6hdr *get_ip6hdr(struct ethhdr *eth,
-                                                  struct hdr_cursor *nh,
-                                                  void *data_end)
-{
-        struct vlan_hdr *vlh = nh->pos;
-        __u16 h_proto = eth->h_proto;
-	struct ipv6hdr *ip6h;
-        int i;
-
-        /* Use loop unrolling to avoid the verifier restriction on loops;
-         * support up to VLAN_MAX_DEPTH layers of VLAN encapsulation.
-         */
-        #pragma unroll
-        for (i = 0; i < VLAN_MAX_DEPTH; i++) {
-                if (!(h_proto == bpf_htons(ETH_P_8021Q) ||
-                      h_proto == bpf_htons(ETH_P_8021AD)))
-                        break;
-
-                if (vlh + 1 > data_end)
-                        return NULL;
-
-                h_proto = vlh->h_vlan_encapsulated_proto;
-                vlh++;
-        }
-
-        ip6h = (void *)vlh;
-
-	if (h_proto != bpf_htons(ETH_P_IPV6))
-		return NULL;
-
-	/* Pointer-arithmetic bounds check; pointer +1 points to after end of
-	 * thing being pointed to. We will be using this style in the remainder
-	 * of the tutorial.
-	 */
-	if (ip6h + 1 > data_end)
-		return NULL;
-
-	nh->pos = ip6h + 1;
-	return ip6h;
-}
-
-static __always_inline struct icmp6hdr *get_icmp6hdr(struct ipv6hdr *ip6h,
-                                                     struct hdr_cursor *nh,
-                                                     void *data_end)
-{
-	struct icmp6hdr *icmp6h = nh->pos;
-
-	if (ip6h->nexthdr != IPPROTO_ICMPV6)
-		return NULL;
-
-	if (icmp6h + 1 > data_end)
-		return NULL;
-
-	nh->pos = icmp6h + 1;
-	return icmp6h;
-}
-
 #endif /* __PARSING_HELPERS_H */