staging: wilc1000: added complete() call for error scenario in handle_key()

During memory allocation failure in handle_key() the complete() was not
called for comp_test_key_block event. So now added the code to call
complete() for event during error scenario.

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