Introduced by 3ddc5b46a8 ("kernel-wide: fix missing validations
on __get/__put/__copy_to/__copy_from_user()").
Also fix some other places which could be problematic in a similar way,
although they hadn't been proved so, as far as I can tell.
Cc: Michael Cree <mcree@orcon.net.nz>
Signed-off-by: Matt Turner <mattst88@gmail.com>
