staging: wilc1000: remove 'hif_thread_comp' completions

Remove 'hif_thread_comp' completions as its not required after adding
completion event as part work data to handle each sync call.

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