deal with shellcheck warnings

repos/system_upgrade/common/actors/livemode/modify_userspace_for_livemode/files/do-upgrade.sh

@@ -215,6 +215,9 @@ do_upgrade() {
     # NOTE: in case we would need to run leapp before pivot, we would need to
     #       specify where the root is, e.g. --root=/sysroot
     # TODO: update: systemd-nspawn
+
+    # NOTE: We disable shell-check since we want to word-break NSPAWN_OPTS
+    # shellcheck disable=SC2046
     /usr/bin/systemd-nspawn $NSPAWN_OPTS -D "$NEWROOT" /usr/bin/bash -c "mount -a; $LEAPPBIN upgrade --resume $args"
     rv=$?
 
@@ -249,6 +252,9 @@ do_upgrade() {
         # all FSTAB partitions. As mount was working before, hopefully will
         # work now as well. Later this should be probably modified as we will
         # need to handle more stuff around storage at all.
+
+        # NOTE: We disable shell-check since we want to word-break NSPAWN_OPTS
+        # shellcheck disable=SC2046
         /usr/bin/systemd-nspawn $NSPAWN_OPTS -D "$NEWROOT" /usr/bin/bash -c "mount -a; /usr/bin/python3 -B $LEAPP3_BIN upgrade --resume $args"
         rv=$?
     fi
@@ -303,6 +309,8 @@ save_journal() {
         local store_cmd="mount -a"
         local store_cmd="$store_cmd; cat /tmp-leapp-upgrade.log >> /var/log/leapp/leapp-upgrade.log"
 
+        # NOTE: We disable shell-check since we want to word-break NSPAWN_OPTS
+        # shellcheck disable=SC2046
         /usr/bin/systemd-nspawn $NSPAWN_OPTS -D "$NEWROOT" /usr/bin/bash -c "$store_cmd"
 
         rm -f $logfile
@@ -317,7 +325,7 @@ save_journal() {
 # during the kernel-core rpm postscript.
 # the result is ro-bind-mounted over /proc/cmdline inside the container.
 awk '{print $1}' /proc/cmdline \
-    | xargs -I@ echo @ $(cat "${NEWROOT}"/var/lib/leapp/.fakerootfs) \
+    | xargs -I@ echo @ "$(cat "${NEWROOT}"/var/lib/leapp/.fakerootfs)" \
     > ${NEWROOT}/var/lib/leapp/.fakecmdline
 
 ##### do the upgrade #######