It's possible to register a chrdev with a name size exactly the same as
was allocated in structure.  It seems it was not intended behaviour.

At least chrdev_show does not like it.
Signed-off-by: NCyrill Gorcunov <gorcunov@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>