Make sure dependency files are generated for assembly files too in the BUILD...

Make sure dependency files are generated for assembly files too in the BUILD build system module. Minor code cleanups.

LUFA/Build/lufa.build.in

@@ -140,12 +140,12 @@ endif
 # Convert input source filenames into a list of required output object files
 OBJECT_FILES := $(addsuffix .o, $(basename $(SRC)))
 ifneq ($(OBJDIR),.)
-   $(shell mkdir $(OBJDIR) 2>&1 | /dev/null)   
+   $(shell mkdir $(OBJDIR) 2>&1 > /dev/null)   
    VPATH           += $(dir $(SRC))
-   
    OBJECT_FILES    := $(addprefix $(patsubst %/,%,$(OBJDIR))/, $(notdir $(OBJECT_FILES)))
 endif
 
+# Create a list of dependency files from the list of object files
 DEPENDENCY_FILES := $(OBJECT_FILES:%.o=%.d)
 
 # Create a list of common flags to pass to the compiler/linker/assembler
@@ -237,7 +237,7 @@ $(OBJDIR)/%.o: %.cpp $(MAKEFILE_LIST)
 	
 $(OBJDIR)/%.o: %.S $(MAKEFILE_LIST)
 	@echo $(MSG_ASSEMBLE_CMD) Assembling \"$(notdir $<)\"
-	$(CROSS)-gcc -c $(BASE_CC_FLAGS) $(BASE_ASM_FLAGS) $(CC_FLAGS) $(ASM_FLAGS) $< -o $@
+	$(CROSS)-gcc -c $(BASE_CC_FLAGS) $(BASE_ASM_FLAGS) $(CC_FLAGS) $(ASM_FLAGS) -MMD -MP -MF $(@:%.o=%.d) $< -o $@
 
 .PRECIOUS  : $(OBJECT_FILES)
 .SECONDARY : %.a