follow-up on the util/recover.c change earlier

It failed in the CI

util/dlb.sln

@@ -0,0 +1,33 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 16
+VisualStudioVersion = 16.0.30907.101
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{911E67C6-3D85-4FCE-B560-20A9C3E3FF48}") = "dlb", "dlb.exe", "{69FE91F4-4A3D-4E77-8BD7-D5D11FFEFFA1}"
+	ProjectSection(DebuggerProjectSystem) = preProject
+		PortSupplier = 00000000-0000-0000-0000-000000000000
+		Executable = C:\Users\MichaelAllison\Documents\github\NHsource\util\dlb.exe
+		RemoteMachine = ALLISONPC2
+		StartingDirectory = C:\Users\MichaelAllison\Documents\github\NHsource\util
+		Arguments = v f ../src/nhdat370
+		Environment = Default
+		LaunchingEngine = 00000000-0000-0000-0000-000000000000
+		UseLegacyDebugEngines = No
+		LaunchSQLEngine = No
+		AttachLaunchAction = No
+	EndProjectSection
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Release|x86 = Release|x86
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{69FE91F4-4A3D-4E77-8BD7-D5D11FFEFFA1}.Release|x86.ActiveCfg = Release|x86
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {D14F79FF-4FDB-4035-944E-EA73CEDF5244}
+	EndGlobalSection
+EndGlobal

util/recover.c

@@ -22,6 +22,10 @@ extern int vms_creat(const char *, unsigned);
 extern int vms_open(const char *, int, unsigned);
 #endif /* VMS */
 
+#ifndef nhUse
+#define nhUse(arg) (void)(arg)
+#endif
+
 int restore_savefile(char *);
 void set_levelfile_name(int);
 int open_levelfile(int);