Staging: otus: Drop an unnecessary NULL test

Apparently, the NULL test is not necessary at this point.

The semantic patch that finds this problem is as follows:
(http://www.emn.fr/x-info/coccinelle/

)

// <smpl>
@@
type T;
expression E;
identifier i,fld;
statement S;
@@

- T i = E->fld;
+ T i;
  ... when != E
      when != i
  if (E == NULL) S
+ i = E->fld;
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Acked-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>