staging: ks7010: move null check before dereference

Function parameter is cast to a local pointer which is then
dereferenced before it is checked to be non-NULL.

Move pointer null check to be before the pointer is dereferenced.

Signed-off-by: Tobin C. Harding <me@tobin.cc>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>