[UR][L0] urDevice when numdevices is not zero (#19103)

When NumDevices is not zero and when phDevice is null, the user cannot
query the number of devices. This addresses that issue.

---------

Signed-off-by: Zhang, Winston <winston.zhang@intel.com>

Author: winstonzhang-intel

unified-runtime/source/adapters/level_zero/device.cpp

@@ -166,12 +166,8 @@ ur_result_t urDeviceGet(
   if (Devices)
     std::copy_n(MatchedDevices.begin(), N, Devices);
 
-  if (NumDevices) {
-    if (*NumDevices == 0)
-      *NumDevices = ZeDeviceCount;
-    else
-      *NumDevices = N;
-  }
+  if (NumDevices)
+    *NumDevices = ZeDeviceCount;
 
   return UR_RESULT_SUCCESS;
 }