staging: ks7010: Delete unnecessary assignments for buffer variables

A few variables were assigned a null pointer despite of the detail
that they were immediately reassigned by the following statement.
Thus remove such unnecessary assignments.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Reviewed-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>