Remove $(CONFIG) from real_install target. It was a typo anyway.

nsprpub/pr/include/md/Makefile.in

@@ -60,7 +60,7 @@ endif
 real_install::
 	$(NSINSTALL) -D $(DESTDIR)$(includedir)/md
 	cp $(srcdir)/$(MDCPUCFG_H) $(DESTDIR)$(includedir)/prcpucfg.h
-	$(NSINSTALL) -t -m 644 $(CONFIG) $(HEADERS) $(DESTDIR)$(includedir)/md
+	$(NSINSTALL) -t -m 644 $(HEADERS) $(DESTDIR)$(includedir)/md
 
 release:: export
 	@echo "Copying machine-dependent prcpucfg.h"