staging: wilc1000: remove the use of goto label in wilc_spi_clear_int_ext()

Remove goto label '_fail_' used in wilc_spi_clear_int_ext(), to avoid
the label name starting with '_'.

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>