initramfs: specify $(src)/gen_initramfs.sh as a prerequisite in Makefile

Specify the dependency directly in the Makefile.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Greg Thelen <gthelen@google.com>

usr/Makefile

@@ -24,7 +24,6 @@ $(obj)/initramfs_data.o: $(obj)/$(datafile_y) FORCE
 # Generate the initramfs cpio archive
 
 hostprogs-y := gen_init_cpio
-initramfs   := $(CONFIG_SHELL) $(srctree)/$(src)/gen_initramfs.sh
 ramfs-input := $(if $(filter-out "",$(CONFIG_INITRAMFS_SOURCE)), \
 			$(shell echo $(CONFIG_INITRAMFS_SOURCE)),-d)
 ramfs-args  := \
@@ -40,7 +39,7 @@ ifneq ($(wildcard $(obj)/$(datafile_d_y)),)
 endif
 
 quiet_cmd_initfs = GEN     $@
-      cmd_initfs = $(initramfs) -o $@ $(ramfs-args) $(ramfs-input)
+      cmd_initfs = $(CONFIG_SHELL) $< -o $@ $(ramfs-args) $(ramfs-input)
 
 targets := $(datafile_y)
 
@@ -52,8 +51,8 @@ $(deps_initramfs): ;
 # 2) There are changes in which files are included (added or deleted)
 # 3) If gen_init_cpio are newer than initramfs_data.cpio
 # 4) Arguments to gen_initramfs.sh changes
-$(obj)/$(datafile_y): $(obj)/gen_init_cpio $(deps_initramfs) FORCE
-	$(Q)$(initramfs) -l $(ramfs-input) > $(obj)/$(datafile_d_y)
+$(obj)/$(datafile_y): $(src)/gen_initramfs.sh $(obj)/gen_init_cpio $(deps_initramfs) FORCE
+	$(Q)$< -l $(ramfs-input) > $(obj)/$(datafile_d_y)
 	$(call if_changed,initfs)
 
 subdir-$(CONFIG_UAPI_HEADER_TEST) += include

usr/gen_initramfs.sh

@@ -235,7 +235,7 @@ arg="$1"
 case "$arg" in
 	"-l")	# files included in initramfs - used by kbuild
 		dep_list="list_"
-		echo "deps_initramfs := $0 \\"
+		echo "deps_initramfs := \\"
 		shift
 		;;
 	"-o")	# generate compressed cpio image named $1