Similar to [1], this patch fixes the same bug in raid10. Also cleanup the
comments.
[1] commit 
2417b9869b81 ("md/raid1: properly indicate failure when ending
                         a failed write request")
Cc: stable@vger.kernel.org
Fixes: 7cee6d4e6035 ("md/raid10: end bio when the device faulty")
Signed-off-by: Wei Shuyu <wsy@dogben.com>
Acked-by: Guoqing Jiang <jiangguoqing@kylinos.cn>
Signed-off-by: Song Liu <song@kernel.org>
 
                /*
                 * When the device is faulty, it is not necessary to
                 * handle write error.
-                * For failfast, this is the only remaining device,
-                * We need to retry the write without FailFast.
                 */
                if (!test_bit(Faulty, &rdev->flags))
                        set_bit(R1BIO_WriteError, &r1_bio->state);
 
                        /*
                         * When the device is faulty, it is not necessary to
                         * handle write error.
-                        * For failfast, this is the only remaining device,
-                        * We need to retry the write without FailFast.
                         */
                        if (!test_bit(Faulty, &rdev->flags))
                                set_bit(R10BIO_WriteError, &r10_bio->state);
                        else {
+                               /* Fail the request */
+                               set_bit(R10BIO_Degraded, &r10_bio->state);
                                r10_bio->devs[slot].bio = NULL;
                                to_put = bio;
                                dec_rdev = 1;