fix format string error in ippool_printaddr()

The variable this->listsize is an unsigned int, but the format
string assumed ptrdiff_t. Found by Coverity.

Change-Id: Ib2a55907adae98f8aa7b079f1c9a3b4fc5f67fc5
Related: CID#188879

lib/ippool.c

@@ -30,7 +30,7 @@ int ippool_printaddr(struct ippool_t *this)
 	printf("Lastdyn %td\n", this->lastdyn - this->member);
 	printf("Firststat %td\n", this->firststat - this->member);
 	printf("Laststat %td\n", this->laststat - this->member);
-	printf("Listsize %td\n", this->listsize);
+	printf("Listsize %u\n", this->listsize);
 
 	for (n = 0; n < this->listsize; n++) {
 		char s[256];