99base: warn on invalid command for initqueue

When 'initqueue' is called with an invalid command it'll generate
invalid job scripts. This will lead to confusing error messages
later on.
So abort in these cases and print out a warning.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Thomas Renninger <trenn@suse.de>

modules.d/99base/initqueue.sh

@@ -42,6 +42,10 @@ exe=$1
 shift
 
 [ -x "$exe" ] || exe=$(command -v $exe)
+if [ -z "$exe" ] ; then
+    echo "Invalid command"
+    exit 1
+fi
 
 {
     [ -n "$onetime" ] && echo '[ -e "$job" ] && rm -f -- "$job"'