usb: musb: dsps: return error code if reset fails

if reset fails, we should return a *negative*
error code, not a positive value.

Tested-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/musb/musb_dsps.c

@@ -652,7 +652,7 @@ static int dsps_musb_reset(struct musb *musb)
 		session_restart = 1;
 	}
 
-	return !session_restart;
+	return session_restart ? 0 : -EPIPE;
 }
 
 static struct musb_platform_ops dsps_ops = {