hwrng: cn10k - Make check_rng_health() return an error code

Currently check_rng_health() returns zero unconditionally.
Make it to output an error code and return it.

Fixes: 38e9791a ("hwrng: cn10k - Add random number generator support")
Signed-off-by: Vladis Dronov <vdronov@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/char/hw_random/cn10k-rng.c

@@ -31,26 +31,23 @@ struct cn10k_rng {
 
 #define PLAT_OCTEONTX_RESET_RNG_EBG_HEALTH_STATE     0xc2000b0f
 
-static int reset_rng_health_state(struct cn10k_rng *rng)
+static unsigned long reset_rng_health_state(struct cn10k_rng *rng)
 {
 	struct arm_smccc_res res;
 
 	/* Send SMC service call to reset EBG health state */
 	arm_smccc_smc(PLAT_OCTEONTX_RESET_RNG_EBG_HEALTH_STATE, 0, 0, 0, 0, 0, 0, 0, &res);
-	if (res.a0 != 0UL)
-		return -EIO;
-
-	return 0;
+	return res.a0;
 }
 
 static int check_rng_health(struct cn10k_rng *rng)
 {
 	u64 status;
-	int err;
+	unsigned long err;
 
 	/* Skip checking health */
 	if (!rng->reg_base)
-		return 0;
+		return -ENODEV;
 
 	status = readq(rng->reg_base + RNM_PF_EBG_HEALTH);
 	if (status & BIT_ULL(20)) {
@@ -58,7 +55,9 @@ static int check_rng_health(struct cn10k_rng *rng)
 		if (err) {
 			dev_err(&rng->pdev->dev, "HWRNG: Health test failed (status=%llx)\n",
 					status);
-			dev_err(&rng->pdev->dev, "HWRNG: error during reset\n");
+			dev_err(&rng->pdev->dev, "HWRNG: error during reset (error=%lx)\n",
+					err);
+			return -EIO;
 		}
 	}
 	return 0;