build: remove dead code parts

gcc-4.6 has a new warning, -Wunused-but-set-variable, which flags
no-op code.

  CC     libiptc/libip4tc.lo
In file included from libiptc/libip4tc.c:118:0:
libiptc/libiptc.c: In function "iptcc_chain_index_delete_chain":
libiptc/libiptc.c:611:32: warning: variable "index_ptr2" set but not used
libiptc/libiptc.c: In function "alloc_handle":
libiptc/libiptc.c:1282:9: warning: variable "len" set but not used
  CC     libiptc/libip6tc.lo
In file included from libiptc/libip6tc.c:113:0:
libiptc/libiptc.c: In function "iptcc_chain_index_delete_chain":
libiptc/libiptc.c:611:32: warning: variable "index_ptr2" set but not used
libiptc/libiptc.c: In function "alloc_handle":
libiptc/libiptc.c:1282:9: warning: variable "len" set but not used
  CC     xtables_multi-iptables-xml.o
iptables-xml.c: In function "do_rule_part":
iptables-xml.c:376:8: warning: variable "thisChain" set but not used
  CC     xtables_multi-ip6tables.o
ip6tables.c: In function "print_firewall":
ip6tables.c:552:10: warning: variable "flags" set but not used

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
diff --git a/ip6tables.c b/ip6tables.c
index a74238c..4df73b8 100644
--- a/ip6tables.c
+++ b/ip6tables.c
@@ -549,7 +549,6 @@
 {
 	const struct xtables_target *target = NULL;
 	const struct ip6t_entry_target *t;
-	uint8_t flags;
 	char buf[BUFSIZ];
 
 	if (!ip6tc_is_chain(targname, handle))
@@ -559,7 +558,6 @@
 		         XTF_LOAD_MUST_SUCCEED);
 
 	t = ip6t_get_target((struct ip6t_entry *)fw);
-	flags = fw->ipv6.flags;
 
 	if (format & FMT_LINENUMBERS)
 		printf(FMT("%-4u ", "%u "), num);
diff --git a/iptables-xml.c b/iptables-xml.c
index dc3cd4f..aa98f75 100644
--- a/iptables-xml.c
+++ b/iptables-xml.c
@@ -373,7 +373,6 @@
 {
 	int arg = 1;		// ignore leading -A
 	char invert_next = 0;
-	char *thisChain = NULL;
 	char *spacer = "";	// space when needed to assemble arguments
 	char *level1 = NULL;
 	char *level2 = NULL;
@@ -397,8 +396,6 @@
 		} else printf("%s<%s ", (leveli ## LEVEL), (level ## LEVEL)); \
 	} while(0)
 
-	thisChain = argv[arg++];
-
 	if (part == 1) {	/* skip */
 		/* use argvattr to tell which arguments were quoted 
 		   to avoid comparing quoted arguments, like comments, to -j, */
diff --git a/libiptc/libiptc.c b/libiptc/libiptc.c
index d3b1c51..0b6d5e3 100644
--- a/libiptc/libiptc.c
+++ b/libiptc/libiptc.c
@@ -608,7 +608,7 @@
  */
 static int iptcc_chain_index_delete_chain(struct chain_head *c, struct xtc_handle *h)
 {
-	struct list_head *index_ptr, *index_ptr2, *next;
+	struct list_head *index_ptr, *next;
 	struct chain_head *c2;
 	unsigned int idx, idx2;
 
@@ -628,7 +628,7 @@
 		 * is located in the same index bucket.
 		 */
 		c2         = list_entry(next, struct chain_head, list);
-		index_ptr2 = iptcc_bsearch_chain_index(c2->name, &idx2, h);
+		iptcc_bsearch_chain_index(c2->name, &idx2, h);
 		if (idx != idx2) {
 			/* Rebuild needed */
 			return iptcc_chain_index_rebuild(h);
@@ -1279,11 +1279,8 @@
 static struct xtc_handle *
 alloc_handle(const char *tablename, unsigned int size, unsigned int num_rules)
 {
-	size_t len;
 	struct xtc_handle *h;
 
-	len = sizeof(STRUCT_TC_HANDLE) + size;
-
 	h = malloc(sizeof(STRUCT_TC_HANDLE));
 	if (!h) {
 		errno = ENOMEM;