kbuild: code refactoring in Makefile.headerinst

No functional changes just improved readability
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

scripts/Makefile.headersinst

@@ -37,6 +37,8 @@ ifeq ($(obj),include/asm-$(ARCH)$(BIASMDIR))
      _dst := include/asm
 endif
 
+install := $(INSTALL_HDR_PATH)/$(_dst)
+
 header-y	:= $(sort $(header-y) $(unifdef-y))
 subdir-y	:= $(patsubst %/,%,$(filter %/, $(header-y)))
 header-y	:= $(filter-out %/, $(header-y))
@@ -45,31 +47,31 @@ header-y	:= $(filter-out %/, $(header-y))
 check-y		:= $(patsubst %,.check.%,$(header-y) $(objhdr-y))
 
 # Work out what needs to be removed
-oldheaders	:= $(patsubst $(INSTALL_HDR_PATH)/$(_dst)/%,%,$(wildcard $(INSTALL_HDR_PATH)/$(_dst)/*.h))
+oldheaders      := $(patsubst $(install)/%,%,$(wildcard $(install)/*.h))
 unwanted        := $(filter-out $(header-y) $(objhdr-y),$(oldheaders))
 
-oldcheckstamps	:= $(patsubst $(INSTALL_HDR_PATH)/$(_dst)/%,%,$(wildcard $(INSTALL_HDR_PATH)/$(_dst)/.check.*.h))
+oldcheckstamps  := $(patsubst $(install)/%,%,$(wildcard $(install)/.check.*.h))
 unwanted        += $(filter-out $(check-y),$(oldcheckstamps))
 
 # Prefix them all with full paths to $(INSTALL_HDR_PATH)
-header-y 	:= $(patsubst %,$(INSTALL_HDR_PATH)/$(_dst)/%,$(header-y))
-objhdr-y 	:= $(patsubst %,$(INSTALL_HDR_PATH)/$(_dst)/%,$(objhdr-y))
-check-y 	:= $(patsubst %,$(INSTALL_HDR_PATH)/$(_dst)/%,$(check-y))
+header-y        := $(patsubst %,$(install)/%,$(header-y))
+objhdr-y        := $(patsubst %,$(install)/%,$(objhdr-y))
+check-y         := $(patsubst %,$(install)/%,$(check-y))
 
 quiet_cmd_o_hdr_install = INSTALL $(patsubst $(INSTALL_HDR_PATH)/%,%,$@)
-      cmd_o_hdr_install   = cp $(patsubst $(INSTALL_HDR_PATH)/$(_dst)/%,$(objtree)/$(obj)/%,$@) \
-			    $(INSTALL_HDR_PATH)/$(_dst)
+      cmd_o_hdr_install = cp $(patsubst $(install)/%,$(objtree)/$(obj)/%,$@) \
+                             $(install)
 
 quiet_cmd_unifdef = UNIFDEF $(patsubst $(INSTALL_HDR_PATH)/%,%,$@)
-      cmd_unifdef	  = $(UNIFDEF) $(patsubst $(INSTALL_HDR_PATH)/$(_dst)/%,$(srctree)/$(obj)/%,$@) \
+      cmd_unifdef = $(UNIFDEF) $(patsubst $(install)/%,$(srctree)/$(obj)/%,$@)\
                                | $(HDRSED) > $@ || :
 
-quiet_cmd_check		  = CHECK   $(patsubst $(INSTALL_HDR_PATH)/$(_dst)/.check.%,$(_dst)/%,$@)
+quiet_cmd_check = CHECK   $(patsubst $(install)/.check.%,$(_dst)/%,$@)
       cmd_check = $(CONFIG_SHELL) $(srctree)/scripts/hdrcheck.sh \
                   $(INSTALL_HDR_PATH)/include $(subst /.check.,/,$@) $@
 
 quiet_cmd_remove = REMOVE  $(_dst)/$@
-      cmd_remove	  = rm -f $(INSTALL_HDR_PATH)/$(_dst)/$@
+      cmd_remove = rm -f $(install)/$@
 
 quiet_cmd_mkdir  = MKDIR   $(patsubst $(INSTALL_HDR_PATH)/%,%,$@)
       cmd_mkdir  = mkdir -p $@
@@ -80,13 +82,14 @@ ifdef HDRCHECK
 __headerscheck: $(subdir-y) $(check-y)
 	@true
 
-$(check-y) : $(INSTALL_HDR_PATH)/$(_dst)/.check.%.h : $(INSTALL_HDR_PATH)/$(_dst)/%.h 
+$(check-y) : $(install)/.check.%.h : $(install)/%.h
 	$(call cmd,check)
 
 # Other dependencies for $(check-y)
 include /dev/null $(wildcard $(check-y))
 
-# ... but leave $(check-y) as .PHONY for now until those deps are actually correct.
+# but leave $(check-y) as .PHONY for now until those
+# deps are actually correct.
 .PHONY: $(check-y)
 
 else
@@ -94,26 +97,29 @@ else
 __headersinst: $(subdir-y) $(header-y) $(objhdr-y)
 	@true
 
-$(objhdr-y) $(subdir-y) $(header-y): | $(INSTALL_HDR_PATH)/$(_dst) $(unwanted)
+$(objhdr-y) $(subdir-y) $(header-y): | $(install) $(unwanted)
 
-$(INSTALL_HDR_PATH)/$(_dst):
+$(install):
 	$(call cmd,mkdir)
 
+# Rules for removing unwanted header files
 .PHONY: $(unwanted)
 $(unwanted):
 	$(call cmd,remove)
 
-$(objhdr-y): $(INSTALL_HDR_PATH)/$(_dst)/%.h: $(objtree)/$(obj)/%.h $(kbuild-file)
+# Install generated files
+$(objhdr-y): $(install)/%.h: $(objtree)/$(obj)/%.h $(kbuild-file)
 	$(call cmd,o_hdr_install)
 
-$(header-y): $(INSTALL_HDR_PATH)/$(_dst)/%.h: $(srctree)/$(obj)/%.h $(kbuild-file)
+# Unifdef header files and install them
+$(header-y): $(install)/%.h: $(srctree)/$(obj)/%.h $(kbuild-file)
 	$(call cmd,unifdef)
 
 endif
 
-hdrinst := -rR -f $(srctree)/scripts/Makefile.headersinst obj
+hdr-inst := -rR -f $(srctree)/scripts/Makefile.headersinst obj
 
 # Recursion
 .PHONY: $(subdir-y)
 $(subdir-y):
-	$(Q)$(MAKE) $(hdrinst)=$(obj)/$@ dst=$(_dst)/$@ rel=../$(rel)
+	$(Q)$(MAKE) $(hdr-inst)=$(obj)/$@ dst=$(_dst)/$@