[client] fix typo on doc API visibility for RecallTable()

The KuduClient::RecallTable() is an exported function/method,
and it's also being referred to in the inline docs for the documented
KuduClient::SoftDeleteTable() API call.  So, it's necessary to
auto-generate the API docs for RecallTable() as well, and this
update moves Doxygen's @endcond tag to achieve that.

There are no functional modifications in this changelist.

This is a follow-up to 7b6b6b636818d3e22a3939fde77689dce84e88b2.

Change-Id: Ic759d2112075959e0203dc0e1eb5a1629ebef7b4
Reviewed-on: http://gerrit.cloudera.org:8080/24593
Tested-by: Kudu Jenkins
Reviewed-by: Marton Greber <greber.mx@gmail.com>