ipf: Remove set but unused variables.

Reported by:	clang
Differential Revision:	https://reviews.freebsd.org/D40667

sbin/ipf/ipmon/ipmon.c

@@ -304,19 +304,17 @@ static icmp_subtype_t *
 find_icmpsubtype(int type, icmp_subtype_t *table, size_t tablesz)
 {
 	icmp_subtype_t *ist;
-	int i;
 
 	if (tablesz < 2)
 		return (NULL);
 
 	if ((type < 0) || (type > table[tablesz - 2].ist_val))
 		return (NULL);
 
-	i = type;
 	if (table[type].ist_val == type)
 		return (table + type);
 
-	for (i = 0, ist = table; ist->ist_val != -2; i++, ist++)
+	for (ist = table; ist->ist_val != -2; ist++)
 		if (ist->ist_val == type)
 			return (ist);
 	return (NULL);
@@ -327,19 +325,17 @@ static icmp_type_t *
 find_icmptype(int type, icmp_type_t *table, size_t tablesz)
 {
 	icmp_type_t *it;
-	int i;
 
 	if (tablesz < 2)
 		return (NULL);
 
 	if ((type < 0) || (type > table[tablesz - 2].it_val))
 		return (NULL);
 
-	i = type;
 	if (table[type].it_val == type)
 		return (table + type);
 
-	for (i = 0, it = table; it->it_val != -2; i++, it++)
+	for (it = table; it->it_val != -2; it++)
 		if (it->it_val == type)
 			return (it);
 	return (NULL);