shellcheck cleanup and root check

lmde-expert.sh

@@ -1,5 +1,10 @@
 #!/bin/bash
 
+if [[ "$(id -u)" -ne 0 ]]; then
+	echo "ERROR: This needs to be run as root"
+	exit 250
+fi
+
 declare -rA SUBVOLS_DEFAULT=(
   ["@home"]="home"
   ["@root"]="root"

lmde-postinstall.sh

@@ -1,5 +1,10 @@
 #!/bin/bash
 
+if [[ "$(id -u)" -ne 0 ]]; then
+	echo "ERROR: This needs to be run as root"
+	exit 250
+fi
+
 apt install -y snapper inotify-tools git make systemd-zram-generator btrfsmaintenance axel
 bash -c "$(curl -fsSL https://pacstall.dev/q/install)"
 
@@ -27,13 +32,13 @@ snapper -c root set-config 'TIMELINE_LIMIT_YEARLY=0'
 
 snapper -c root create --description "Fresh install"
 
-cd /tmp
+cd /tmp || exit 240
 git clone https://github.com/Antynea/grub-btrfs.git
-cd grub-btrfs
+cd grub-btrfs || exit 240
 make install
 systemctl enable --now grub-btrfsd
 update-grub2
-cd /tmp
+cd /tmp || exit 240
 rm -rf grub-btrfs
 
 echo "zram-size = 2048" >> /etc/systemd/zram-generator.conf
@@ -41,4 +46,4 @@ echo "compression-algorithm = zstd" >> /etc/systemd/zram-generator.conf
 
 systemctl enable --now btrfs-{scrub,balance,trim}.timer
 
-popd
+popd || exit 240