kdumpctl: remove some legacy code

It seems the save_core function and vmcore detection was used a long
time ago when kdump shares same userspace in first and second kernel.
It's now heavily deprecated (only support cp, hardcoded path, dumpoops
no longer exists) and not used.

Now vmcore will never show up in first kernel for both kdump and fadump
case, and kdumpctl is only used in first kernel, so just remove them.

Signed-off-by: Kairui Song <kasong@tencent.com>
Acked-by: Coiby Xu <coxu@redhat.com>

kdumpctl

@@ -72,32 +72,6 @@ determine_dump_mode()
 	ddebug "DEFAULT_DUMP_MODE=$DEFAULT_DUMP_MODE"
 }
 
-save_core()
-{
-	coredir="/var/crash/$(date +"%Y-%m-%d-%H:%M")"
-
-	mkdir -p "$coredir"
-	ddebug "cp --sparse=always /proc/vmcore $coredir/vmcore-incomplete"
-	if cp --sparse=always /proc/vmcore "$coredir/vmcore-incomplete"; then
-		mv "$coredir/vmcore-incomplete" "$coredir/vmcore"
-		dinfo "saved a vmcore to $coredir"
-	else
-		derror "failed to save a vmcore to $coredir"
-	fi
-
-	# pass the dmesg to Abrt tool if exists, in order
-	# to collect the kernel oops message.
-	# https://fedorahosted.org/abrt/
-	if [[ -x /usr/bin/dumpoops ]]; then
-		ddebug "makedumpfile --dump-dmesg $coredir/vmcore $coredir/dmesg"
-		makedumpfile --dump-dmesg "$coredir/vmcore" "$coredir/dmesg" > /dev/null 2>&1
-		ddebug "dumpoops -d $coredir/dmesg"
-		if dumpoops -d "$coredir/dmesg" > /dev/null 2>&1; then
-			dinfo "kernel oops has been collected by abrt tool"
-		fi
-	fi
-}
-
 rebuild_fadump_initrd()
 {
 	if ! $MKFADUMPRD "$DEFAULT_INITRD_BAK" "$TARGET_INITRD" --kver "$KDUMP_KERNELVER"; then
@@ -1346,12 +1320,7 @@ main()
 
 	case "$1" in
 	start)
-		if [[ -s /proc/vmcore ]]; then
-			save_core
-			reboot
-		else
-			start
-		fi
+		start
 		;;
 	stop)
 		stop