staging: wilc1000: Use sizeof type *pointer instead of sizeof type

The patch uses the size of the dereference to a variable instead of it's type,
to make the code more resistant to type changes in the future. The type of the
pointer variable here is the same as the type in the argument that is being
replaced in sizeof().

Signed-off-by: sayli karnik <karniksayli1995@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>