ocfs2: remove some redundant casting

ocfs2: remove some redundant casting

There are two standard techniques for dereferencing structures pointed
to by void *: cast to the right type each time they're used, or assign
to local variables of the right type.

But there's no need to do *both*.

Signed-off-by: George Spelvin <[email protected]>
Cc: Mark Fasheh <[email protected]>
Acked-by: Joel Becker <[email protected]>
Reviewed-by: Jie Liu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>