call systemctl in subshell to prevent the explorer from failing if it exits non zero

Signed-off-by: Steven Armstrong <steven@icarus.ethz.ch>

cdist/conf/type/__start_on_boot/explorer/state

@@ -28,14 +28,9 @@ name="$__object_id"
 
 case "$os" in
     archlinux)
-        # convert bash array to shell
-        systemctl is-enabled "$name" >/dev/null 2>&1; ret=$?
-
-        if [ "$ret" = 0 ]; then
-            state="present"
-        else
-            state="absent"
-        fi
+        state=$(systemctl is-enabled "$name" >/dev/null 2>&1 \
+            && echo present \
+            || echo absent)
     ;;
 
     debian|ubuntu|openwrt)