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/[email protected]
Signed-off-by: Joseph Qi <[email protected]>
Reviewed-by: Eric Ren <[email protected]>
Cc: Mark Fasheh <[email protected]>
Cc: Joel Becker <[email protected]>
Cc: Junxiao Bi <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>