staging: wilc1000: use correct 'struct remain_ch' variable in scan complete

Use the correct reference to remain_ch variable in scan complete.
Passing 'msg->body.remain_on_ch' to handle_remain_on_chan is not
correct. So used the correct reference used to store roc related
information during the scan.

Signed-off-by: Ajay Singh <ajay.kathat@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>