ocfs2: fix type conversion risk when get cluster attributes

In o2nm_cluster, cl_idle_timeout_ms, cl_keepalive_delay_ms, as well as
cl_reconnect_delay_ms, are defined as type of unsigned int.  So we
should also use unsigned int in the helper functions.

Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>