Change log level of Event_Sync_State

We need the log information of Event_Sync_State to test if the SYN_DROPPED
event is handled correctly.

BUG=chromium-os:28997
TEST=there should be lines containing 'Event_Sync_State' in /var/log/Xorg.0.log

Change-Id: I95225a6fe8a87641480595231df44b2eaaf0788a
diff --git a/src/libevdev_event.c b/src/libevdev_event.c
index 4fcc520..5100d07 100644
--- a/src/libevdev_event.c
+++ b/src/libevdev_event.c
@@ -371,9 +371,11 @@
 
     Event_Get_Time(&device->after_sync_time, device->info.is_monotonic);
 
-    LOG_DEBUG(device, "Event_Sync_State: before %ld.%ld after %ld.%ld\n",
-              device->before_sync_time.tv_sec, device->before_sync_time.tv_usec,
-              device->after_sync_time.tv_sec, device->after_sync_time.tv_usec);
+    LOG_WARNING(device, "Event_Sync_State: before %ld.%ld after %ld.%ld\n",
+                device->before_sync_time.tv_sec,
+                device->before_sync_time.tv_usec,
+                device->after_sync_time.tv_sec,
+                device->after_sync_time.tv_usec);
 }
 
 static void