fabrics: fix some memory leaks

fabrics: fix some memory leaks

None of these are critical for "nvme discover" or "nvme connect-all".
Still, silencing valgrind's error messages by fixing them gives some
peace of mind, and a longer-running program like the forthcomint
nvme monitor, leak checks are more important.

Use the previously introduced cleanup macros for this purpose.

Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>