recovery: free recovery info before stopping recovery

Without this patch, the recovery thread cannot start the next recovery
and the stopped recovery cannot start any more.

Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Signed-off-by: Liu Yuan <namei.unix@gmail.com>

Conflicts:
	sheep/recovery.c

Manually modified by Hitoshi Mitake <mitake.hitoshi@lab.ntt.co.jp>.
Only modifying the call from sd_debug() to sd_dprintf().

Signed-off-by: Hitoshi Mitake <mitake.hitoshi@lab.ntt.co.jp>
sheepdog stable release v0.6.2

Signed-off-by: Hitoshi Mitake <mitake.hitoshi@lab.ntt.co.jp>