USB: adutux: fix misuse of return value of copy_to_user()

copy_to_user() returns number of not copied bytes, not error code.

Signed-off-by: Kulikov Vasiliy <segooon@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/misc/adutux.c b/drivers/usb/misc/adutux.c
index d240de097c6211afd6ff2ef1399c1b2add9ca751..801324af9470a08d5b42011bfa397a03d97cb99d 100644 (file)
--- a/drivers/usb/misc/adutux.c
+++ b/drivers/usb/misc/adutux.c
@@ -439,7 +439,7 @@ static ssize_t adu_read(struct file *file, __user char *buffer, size_t count,
                        /* drain secondary buffer */
                        int amount = bytes_to_read < data_in_secondary ? bytes_to_read : data_in_secondary;
                        i = copy_to_user(buffer, dev->read_buffer_secondary+dev->secondary_head, amount);
-                       if (i < 0) {
+                       if (i) {
                                retval = -EFAULT;
                                goto exit;
                        }