[RESEND] tcmu: fix error resetting qfull_time_out to default

[Prasanna Kumar Kalever <prasanna.kalever@xxxxxxxxxx>]

Problem:
-------
$ cat /sys/kernel/config/target/core/user_0/block/attrib/qfull_time_out
-1

$ echo "-1" > /sys/kernel/config/target/core/user_0/block/attrib/qfull_time_out
-bash: echo: write error: Invalid argument

Fix:
---
This patch will help reset qfull_time_out to its default i.e. qfull_time_out=-1

Signed-off-by: Prasanna Kumar Kalever <prasanna.kalever@xxxxxxxxxx>
---
 drivers/target/target_core_user.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index 4ad89ea71a70..4f26bdc3d1dc 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -2121,6 +2121,8 @@ static ssize_t tcmu_qfull_time_out_store(struct config_item *item,
 
 	if (val >= 0) {
 		udev->qfull_time_out = val * MSEC_PER_SEC;
+	} else if (val == -1) {
+		udev->qfull_time_out = val;
 	} else {
 		printk(KERN_ERR "Invalid qfull timeout value %d\n", val);
 		return -EINVAL;
-- 
2.14.3