ocfs2/dlm: Ignore LVBs of locks in the Blocked list

During lock resource migration, o2dlm fills the packet with a LVB from the
first valid lock. For sanity, it ensures that the other valid locks have the
same LVB. If not, it BUGs.

The valid locks are ones that have granted EX or PR lock levels and are either
on the Granted or Converting lists. Locks in the Blocked list cannot have a
valid LVB.

This patch ensures that we skip the locks in the Blocked list.

Fixes oss bugzilla#1202
http://oss.oracle.com/bugzilla/show_bug.cgi?id=1202

Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>