libxc: fix mmap leak in xc_unmap_domain_meminfo/xc_map_domain_meminfo

libxc: fix mmap leak in xc_unmap_domain_meminfo/xc_map_domain_meminfo

xc_unmap_domain_meminfo uses P2M_FLL_ENTRIES macro instead of P2M_FL_ENTRIES.
Moreover, P2M_FL_ENTRIES macro uses (dinfo->p2m_size) which is always 0 here
as we don't initialize it. The result is that we always unmap just 1 frame.

xc_map_domain_meminfo uses P2M_FLL_ENTRIES macro instead of P2M_FL_ENTRIES
on failure path.

The issue went unnoticed mostly because we use unmap_domain_meminfo and
xc_map_domain_meminfo in one-shot xen-mfndump and xen-hptool (through
xc_exchange_page()) tools. When used is long-running apps (e.g. in xl)
domains become zombies after their death.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>