staging: wilc1000: remove variable rxq_thread_started

rxq_thread_started is initiallized but never used in the driver. Remove
the variable and init code line.

Signed-off-by: Glen Lee <glen.lee@atmel.com>
Signed-off-by: Tony Cho <tony.cho@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>