libcgroup.map: include cgroup_get_cgroup_name

libcgroup.map: include cgroup_get_cgroup_name

Using cgroup_get_cgroup_name() API, fails with:

gcc -o cgrp_get_cgrp_name cgrp_get_cgrp_name.c -lcgroup
/usr/bin/ld: /tmp/ccIyBv5c.o: in function `main':
cgrp_get_cgrp_name.c:(.text+0xaa): undefined reference to `cgroup_get_cgroup_name'
collect2: error: ld returned 1 exit status

The API was introduced by commit ca32d88ef56b1 ("wrappers: Add a
cgroup_get_cgroup_name API") but missed adding it to libcgroup.map file,
causing the linkage issue. Fix the issue by adding the API at the
libcgroup.map under version it was introduced.

Fixes: https://github.com/libcgroup/libcgroup/issues/459
Reported-by: Ron Nazarov <ron@noisytoot.org>
Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com>
(cherry picked from commit 861a9369d234739a9a3bcf8419ba6be9c8af40dc)