[openwrt/openwrt] base-files: upgrade: fix initramfs detection

[LEDE Commits]

dangole pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/20d847d1338f716fc9f143f633b6f79ba6017b5c

commit 20d847d1338f716fc9f143f633b6f79ba6017b5c
Author: Robert Marko <robimarko at gmail.com>
AuthorDate: Sun Dec 20 18:02:53 2020 +0100

    base-files: upgrade: fix initramfs detection
    
    Commit "initramfs: switch to tmpfs to fix ujail" switched initramfs to
    now use tmpfs, it causes $(rootfs_type) to now return tmpfs when
    running initramfs image instead of being empty.
    
    This broke initramfs detection which prevents config files from
    being saved as it does not work from initramfs.
    
    So, lets test for $(rootfs_type) returning "tmpfs" instead.
    
    Fixes: 7fd3c68 ("initramfs: switch to tmpfs to fix ujail)
    
    Signed-off-by: Robert Marko <robimarko at gmail.com>
---
 package/base-files/Makefile              | 2 +-
 package/base-files/files/sbin/sysupgrade | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/package/base-files/Makefile b/package/base-files/Makefile
index fbcb694592..fb1267ea5b 100644
--- a/package/base-files/Makefile
+++ b/package/base-files/Makefile
@@ -12,7 +12,7 @@ include $(INCLUDE_DIR)/version.mk
 include $(INCLUDE_DIR)/feeds.mk
 
 PKG_NAME:=base-files
-PKG_RELEASE:=240
+PKG_RELEASE:=241
 PKG_FLAGS:=nonshared
 
 PKG_FILE_DEPENDS:=$(PLATFORM_DIR)/ $(GENERIC_PLATFORM_DIR)/base-files/
diff --git a/package/base-files/files/sbin/sysupgrade b/package/base-files/files/sbin/sysupgrade
index ca2eb298dc..3300d8e1ea 100755
--- a/package/base-files/files/sbin/sysupgrade
+++ b/package/base-files/files/sbin/sysupgrade
@@ -216,7 +216,7 @@ include /lib/upgrade
 do_save_conffiles() {
 	local conf_tar="$1"
 
-	[ -z "$(rootfs_type)" ] && {
+	[ "$(rootfs_type)" = "tmpfs" ] && {
 		echo "Cannot save config while running from ramdisk." >&2
 		ask_bool 0 "Abort" && exit
 		rm -f "$conf_tar"