ocfs2: remove obscure BUG_ON in dlmglue

ocfs2: remove obscure BUG_ON in dlmglue

These BUG_ON(!inode) are obscure because we have already used inode to
get osb.  And actually we can guarantee here inode is valid in the
context.  So we can safely remove them.

Link: http://lkml.kernel.org/r/5776336A.6030104@huawei.com
Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Reviewed-by: Eric Ren <zren@suse.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>