src: print count variable in normal set listings

src: print count variable in normal set listings

Also print the number of allocated set elements if the set provided
an upper size limit and there is at least one element.

Example:

table ip t {
   set s {
       type ipv4_addr
       size 65535      # count 1
       flags dynamic
       counter
       elements = { 1.1.1.1 counter packets 1 bytes 11 }
   }
   ...

JSON output is unchanged as this only has informational purposes.

This change breaks tests, followup patch addresses this.

Suggested-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>