[NTOS:PNP] IopGetBusTypeGuidIndex(): Remove 1 unwanted ExFreePool()

in a failure case.

CORE-12791

Author: SergeGautherie

ntoskrnl/io/pnpmgr/pnpmgr.c

@@ -445,7 +445,6 @@ IopGetBusTypeGuidIndex(LPGUID BusTypeGuid)
         if (!NewList)
         {
             /* Fail */
-            ExFreePool(PnpBusTypeGuidList);
             goto Quickie;
         }