base-files: move stage2 upgrade to separated file

do_upgrade_stage2() isn't really any common code. It isn't used anywhere
except for /sbin/sysupgrade that passes it to the stage2.

Moving its code to separated file also simplifies COMMAND variable.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
(cherry picked from commit f7edd94a65)

package/base-files/files/lib/upgrade/common.sh

@@ -225,25 +225,3 @@ default_do_upgrade() {
 	fi
 	[ $? -ne 0 ] && exit 1
 }
-
-do_upgrade_stage2() {
-	v "Performing system upgrade..."
-	if type 'platform_do_upgrade' >/dev/null 2>/dev/null; then
-		platform_do_upgrade "$IMAGE"
-	else
-		default_do_upgrade "$IMAGE"
-	fi
-
-	if [ "$SAVE_CONFIG" -eq 1 ] && type 'platform_copy_config' >/dev/null 2>/dev/null; then
-		platform_copy_config
-	fi
-
-	v "Upgrade completed"
-	sleep 1
-
-	v "Rebooting system..."
-	umount -a
-	reboot -f
-	sleep 5
-	echo b 2>/dev/null >/proc/sysrq-trigger
-}

package/base-files/files/lib/upgrade/do_stage2

@@ -0,0 +1,25 @@
+#!/bin/sh
+
+. /lib/functions.sh
+
+include /lib/upgrade
+
+v "Performing system upgrade..."
+if type 'platform_do_upgrade' >/dev/null 2>/dev/null; then
+	platform_do_upgrade "$IMAGE"
+else
+	default_do_upgrade "$IMAGE"
+fi
+
+if [ "$SAVE_CONFIG" -eq 1 ] && type 'platform_copy_config' >/dev/null 2>/dev/null; then
+	platform_copy_config
+fi
+
+v "Upgrade completed"
+sleep 1
+
+v "Rebooting system..."
+umount -a
+reboot -f
+sleep 5
+echo b 2>/dev/null >/proc/sysrq-trigger

package/base-files/files/lib/upgrade/stage2

@@ -59,7 +59,7 @@ switch_to_ramfs() {
 		local file="$(which "$binary" 2>/dev/null)"
 		[ -n "$file" ] && install_bin "$file"
 	done
-	install_file /etc/resolv.conf /lib/*.sh /lib/functions/*.sh /lib/upgrade/*.sh $RAMFS_COPY_DATA
+	install_file /etc/resolv.conf /lib/*.sh /lib/functions/*.sh /lib/upgrade/*.sh /lib/upgrade/do_stage2 $RAMFS_COPY_DATA
 
 	[ -L "/lib64" ] && ln -s /lib $RAM_ROOT/lib64
 

package/base-files/files/sbin/sysupgrade

@@ -363,7 +363,7 @@ fi
 install_bin /sbin/upgraded
 v "Commencing upgrade. Closing all shell sessions."
 
-COMMAND='. /lib/functions.sh; include /lib/upgrade; do_upgrade_stage2'
+COMMAND='/lib/upgrade/do_stage2'
 
 if [ -n "$FAILSAFE" ]; then
 	printf '%s\x00%s\x00%s' "$RAM_ROOT" "$IMAGE" "$COMMAND" >/tmp/sysupgrade