staging: lustre: selftest: freeing an error pointer

We should just return directly if memdup_user() fails. The current code
tries to free "param" which is an error pointer so it will Oops.

Fixes: 2baddf262e ("staging: lustre: use memdup_user to allocate memory and copy from user")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lnet/selftest/conctl.c

@@ -650,10 +650,8 @@ static int lst_test_add_ioctl(struct lstio_test_args *args)
 	if (args->lstio_tes_param) {
 		param = memdup_user(args->lstio_tes_param,
 				    args->lstio_tes_param_len);
-		if (IS_ERR(param)) {
+		if (IS_ERR(param))
-			rc = PTR_ERR(param);
+			return PTR_ERR(param);
-			goto out;
-		}
 	}
 
 	rc = -EFAULT;