ppc4xx: replace sscanf() by kstrtoul()

index df7704053d91..e2b5129c5f84 100644
@@ -4319,6 +4319,7 @@ static ssize_t enable_store(struct device_driver *dev, const char *buf,
 			    size_t count)
 {
 	unsigned long val;
+	int err;
 
 	if (!count || count > 11)
 		return -EINVAL;

@@ -4327,7 +4328,10 @@ static ssize_t enable_store(struct device_driver *dev, const char *buf,
 		return -EFAULT;
 
 	/* Write a key */
-	sscanf(buf, "%lx", &val);
+	err = kstrtoul(buf, 16, &val);
+	if (err)
+		return err;
+
 	dcr_write(ppc440spe_mq_dcr_host, DCRN_MQ0_XORBA, val);
 	isync();
 

@@ -4368,7 +4372,7 @@ static ssize_t poly_store(struct device_driver *dev, const char *buf,
 			  size_t count)
 {
 	unsigned long reg, val;
-
+	int err;
 #ifdef CONFIG_440SP
 	/* 440SP uses default 0x14D polynomial only */
 	return -EINVAL;

@@ -4378,7 +4382,9 @@ static ssize_t poly_store(struct device_driver *dev, const char *buf,
 		return -EINVAL;
 
 	/* e.g., 0x14D or 0x11D */
-	sscanf(buf, "%lx", &val);
+	err = kstrtoul(buf, 16, &val);
+	if (err)
+		return err;
 
 	if (val & ~0x1FF)
 		return -EINVAL;