Keep the root filesystem guard reachable when extraction fails

source_remote imageboot.sh is the last thing the diskless cmdline hook
runs, so returning early on a failed extraction ended the hook and left
dracut to time out. Falling through instead reaches the existing
/sysroot/sbin/init guard, which reports the failure and holds the node so
it stays reachable over ssh, as it did before extraction was checked.

confluent_osdeploy/el10-diskless/profiles/default/scripts/imageboot.sh

@@ -55,7 +55,7 @@ if [ "untethered" = "$(getarg confluent_imagemethod)" -o "uncompressed" = "$(get
     else
         mount -t tmpfs disklessroot /sysroot
     fi
-    extract_untethered_rootimg || return 1
+    extract_untethered_rootimg
 else
     TETHERED=1
     mount -o discard /dev/zram0 /mnt/overlay

confluent_osdeploy/el9-diskless/profiles/default/scripts/imageboot.sh

@@ -55,7 +55,7 @@ if [ "untethered" = "$(getarg confluent_imagemethod)" -o "uncompressed" = "$(get
     else
         mount -t tmpfs disklessroot /sysroot
     fi
-    extract_untethered_rootimg || return 1
+    extract_untethered_rootimg
 else
     TETHERED=1
     mount -o discard /dev/zram0 /mnt/overlay

confluent_osdeploy/ubuntu20.04-diskless/profiles/default/scripts/imageboot.sh

@@ -65,7 +65,7 @@ elif grep -q confluent_imagemethod=uncompressed /proc/cmdline; then
     mount -t tmpfs disklessroot /sysroot
 fi
 if [ "$TETHERED" = 0 ]; then
-    extract_untethered_rootimg || return 1
+    extract_untethered_rootimg
 elif [ ! -f /tmp/mountparts.sh ]; then
     mkdir -p /mnt/overlay/upper /mnt/overlay/work
     mount -t overlay -o upperdir=/mnt/overlay/upper,workdir=/mnt/overlay/work,lowerdir=/mnt/remote disklessroot /sysroot