BUG/MINOR: cli: Fix memory leak

Valgrind's memcheck reports memory leaks in cli.c, because
the out parameter of memprintf is not properly freed:

  ==31035== 11 bytes in 1 blocks are definitely lost in loss record 16 of 101
  ==31035==    at 0x4C2DB8F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
  ==31035==    by 0x4C2FDEF: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
  ==31035==    by 0x4A3C72: my_realloc2 (standard.h:1364)
  ==31035==    by 0x4A3C72: memvprintf (standard.c:3459)
  ==31035==    by 0x4A3D93: memprintf (standard.c:3482)
  ==31035==    by 0x4AF77E: mworker_cli_sockpair_new (cli.c:2324)
  ==31035==    by 0x48E826: init (haproxy.c:1749)
  ==31035==    by 0x408BBC: main (haproxy.c:2725)
  ==31035==
  ==31035== 11 bytes in 1 blocks are definitely lost in loss record 17 of 101
  ==31035==    at 0x4C2DB8F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
  ==31035==    by 0x4C2FDEF: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
  ==31035==    by 0x4A3C72: my_realloc2 (standard.h:1364)
  ==31035==    by 0x4A3C72: memvprintf (standard.c:3459)
  ==31035==    by 0x4A3D93: memprintf (standard.c:3482)
  ==31035==    by 0x4AF071: mworker_cli_proxy_create (cli.c:2172)
  ==31035==    by 0x48EC89: init (haproxy.c:1760)
  ==31035==    by 0x408BBC: main (haproxy.c:2725)

These leaks were introduced in commits
ce83b4a5dd48c000dec68f9d551945d21e9ac7ac and
8a02257d88276e2f2f10c407d2961995f74a192c
which are specific to haproxy 1.9 dev.
1 file changed