ASoC: atmel: Fix error handling in at91samg20ek probe()

The error handling in the AT91SAM9G20-EK machine driver probe did not
consistently free the SSC in error paths, sometimes immediately returning
an error rather than doing cleanup. Fix this.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Link: https://lore.kernel.org/r/20220325154241.1600757-3-broonie@kernel.org