staging: wilc1000: remove unused return variable

In this function,removed the unused integer variable as it is not
actually used to return function success or failure. Return is a pointer
to net_device structure.

Signed-off-by: HariPrasath Elango <hariprasath.elango@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>