fix make for a21, PIDs are always ints, linter things

user/Makefile

@@ -19,14 +19,16 @@ $(APPS): $(BUILDDIR)/init.o
 
 # recipe for compiling imgbuilder
 $(IMGBUILDER): imgbuilder.cc $(MAKEFILE_LIST)
-	@echo "CC		$@"
-	@if test \( ! \( -d $(@D) \) \) ;then mkdir -p $(@D);fi
+	@echo "CXX		$@"
+	@mkdir -p $(@D)
 	$(VERBOSE) $(CXX) -std=c++23 -o $@ $<
 
-# recipe for building the final oostubs image
+.ONESHELL:
+# recipe for building the initrd image
 $(INITRD): $(APPS) $(IMGBUILDER)
 	@echo "IMGBUILD	$@"
-	@if test \( ! \( -d $(@D) \) \) ;then mkdir -p $(@D);fi
+	@mkdir -p $(@D)
+	if [ -z "$(APPS)" ] ; then touch $@ ; exit 0 ; fi
 	$(VERBOSE) $(IMGBUILDER) $(addsuffix $(BUILDDIR)/app.img, $(APPS)) > $@
 
 lint::