[NTOS:MM] Fix memory leak in NtAllocateVirtualMemory

When an allocated VAD's insertion fails, the VAD is not freed. This commit attempts to fix this behaviour.

ntoskrnl/mm/ARM3/virtual.c

@@ -4787,6 +4787,7 @@ NtAllocateVirtualMemory(IN HANDLE ProcessHandle,
         if (!NT_SUCCESS(Status))
         {
             DPRINT1("Failed to insert the VAD!\n");
+            ExFreePoolWithTag(Vad, 'SdaV');
             goto FailPathNoLock;
         }