scsi: megaraid_sas: Use memdup_user() rather than duplicating its implementation

Reuse existing functionality from memdup_user() instead of keeping
duplicate source code.

This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Acked by: Sumit Saxena <sumit.saxena@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/megaraid/megaraid_sas_base.c

@@ -6711,14 +6711,9 @@ static int megasas_mgmt_ioctl_fw(struct file *file, unsigned long arg)
 	unsigned long flags;
 	u32 wait_time = MEGASAS_RESET_WAIT_TIME;
 
-	ioc = kmalloc(sizeof(*ioc), GFP_KERNEL);
-	if (!ioc)
-		return -ENOMEM;
-
-	if (copy_from_user(ioc, user_ioc, sizeof(*ioc))) {
-		error = -EFAULT;
-		goto out_kfree_ioc;
-	}
+	ioc = memdup_user(user_ioc, sizeof(*ioc));
+	if (IS_ERR(ioc))
+		return PTR_ERR(ioc);
 
 	instance = megasas_lookup_instance(ioc->host_no);
 	if (!instance) {