ASoC: AMD: Fix build warning

Fixes
sound/soc/amd/acp-da7219-max98357a.c: In function 'cz_probe':
sound/soc/amd/acp-da7219-max98357a.c:367:3: warning: 'ret' may
be used uninitialized in this function [-Wmaybe-uninitialized]
   dev_err(&pdev->dev, "Failed to register regulator: %d\n",
ret);

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Akshu Agrawal <akshu.agrawal@amd.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/amd/acp-da7219-max98357a.c

@@ -365,7 +365,7 @@ static int cz_probe(struct platform_device *pdev)
 				       &acp_da7219_cfg);
 	if (IS_ERR(rdev)) {
 		dev_err(&pdev->dev, "Failed to register regulator: %d\n",
-			ret);
+			(int)PTR_ERR(rdev));
 		return -EINVAL;
 	}