build: cleanup tmp/ dir of target rootfs

Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>

include/rootfs.mk

@@ -80,6 +80,7 @@ define prepare_rootfs
 	@-find $(1) -name .svn  | $(XARGS) rm -rf
 	@-find $(1) -name .git  | $(XARGS) rm -rf
 	@-find $(1) -name '.#*' | $(XARGS) rm -f
+	rm -rf $(1)/tmp/*
 	rm -f $(1)/usr/lib/opkg/lists/*
 	rm -f $(1)/usr/lib/opkg/info/*.postinst*
 	rm -f $(1)/usr/lib/opkg/info/*.prerm*

package/Makefile

@@ -63,7 +63,7 @@ endif
 $(curdir)/install: $(TMP_DIR)/.build $(curdir)/merge $(if $(CONFIG_TARGET_PER_DEVICE_ROOTFS),$(curdir)/merge-index)
 	- find $(STAGING_DIR_ROOT) -type d | $(XARGS) chmod 0755
 	rm -rf $(TARGET_DIR) $(TARGET_DIR_ORIG)
-	[ -d $(TARGET_DIR)/tmp ] || mkdir -p $(TARGET_DIR)/tmp
+	mkdir -p $(TARGET_DIR)/tmp
 	$(call opkg,$(TARGET_DIR)) install \
 		$(call opkg_package_files,$(shell cat $(PACKAGE_INSTALL_FILES) 2>/dev/null))
 	@for file in $(PACKAGE_INSTALL_FILES); do \