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

user/Makefile.app

@@ -41,7 +41,7 @@ $(BUILDDIR)/app: $(INITOBJ)  $(ASM_OBJECTS) $(CC_OBJECTS) $(LINKER_SCRIPT) $(MAK
 $(BUILDDIR)/app.img: $(BUILDDIR)/app
 	@echo "OBJCOPY		$@"
 	@if ! nm $< | grep "4000000 T start" >/dev/null 2>&1 ; then echo "Symbol 'start' is not first address" ; exit 1 ; fi
-	@if test \( ! \( -d $(@D) \) \) ;then mkdir -p $(@D);fi
+	@mkdir -p $(@D)
 	$(VERBOSE) objcopy -O binary --set-section-flags .bss=alloc,load,contents $< $@
 
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