ASoC: sdw_utils: Fix potential NULL pointer deref in is_sdca_endpoint_present()

Check the return value of kzalloc() and exit early to avoid a potential
NULL pointer dereference.

Cc: stable@vger.kernel.org
Fixes: 4f8ef33d ("ASoC: soc_sdw_utils: skip the endpoint that doesn't present")
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Link: https://patch.msgid.link/20250610103225.1475-2-thorsten.blum@linux.dev


Signed-off-by: Mark Brown <broonie@kernel.org>