setupapi: Demote ERR on opening driver key to a TRACE.

open_driver_key() is called by create_driver_key() and SetupDiOpenDevRegKey()
which depend on the failure path to detect the presence of the key.

This causes a lot of unnecessary errors being printed out.

Signed-off-by: Arkadiusz Hiler <ahiler@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>

dlls/setupapi/devinst.c

@@ -560,7 +560,7 @@ static LONG open_driver_key(struct device *device, REGSAM access, HKEY *key)
             RegCloseKey(class_key);
             return l;
         }
-        ERR("Failed to open driver key, error %u.\n", l);
+        TRACE("Failed to open driver key, error %u.\n", l);
     }
 
     RegCloseKey(class_key);