Add missing forward reference

xtldr/includes/xtldr.h

@@ -37,6 +37,11 @@ XTCDECL
 VOID
 BlClearConsoleScreen();
 
+XTCDECL
+EFI_STATUS
+BlCloseProtocol(IN PEFI_HANDLE Handle,
+                IN PEFI_GUID ProtocolGuid);
+
 XTCDECL
 EFI_STATUS
 BlCloseVolume(IN PEFI_HANDLE VolumeHandle);