[PATCH] usb: Fix timeout detection in usb_control_msg

[Francois Berder]

The loop exits once timeout variable reaches 0.
However, due to the post-decrement operator, timeout
is decremented and set to -1 upon exiting the loop
if a timeout occurs. This means that:
  - a break in the last loop iteration was considered
  a timeout
  - actual timeouts did not return -ETIMEDOUT

Fix comparing timeout variable to -1 instead of 0 to
detect timeouts.

Found with smatch.

Fixes: 2fc8638403c7 ("usb: Assimilate usb_get_descriptor() to linux")
Signed-off-by: Francois Berder <fberder at outlook.fr>
---
 common/usb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/common/usb.c b/common/usb.c
index 6a4ad346f4b..5905b2b5d7b 100644
--- a/common/usb.c
+++ b/common/usb.c
@@ -259,7 +259,7 @@ int usb_control_msg(struct usb_device *dev, unsigned int pipe,
 		mdelay(1);
 	}
 
-	if (timeout == 0)
+	if (timeout == -1)
 		return -ETIMEDOUT;
 
 	if (dev->status)
-- 
2.43.0