lsipc: don't free shm data if no shm id is found

lsipc: don't free shm data if no shm id is found

There is a segfault in do_shm_global() when ipc_shm_get_info() return 0 and
ipc_shm_free_info() is called.

When no shm id is found, the memory allocated in shmds by ipc_shm_get_info() is
already free when ipc_shm_free_info() is called.

Move ipc_shm_free_info(shmds) inside the if statement where at least one shm id
is found.

Signed-off-by: Romain Naour <romain.naour@gmail.com>