fix(_comp_compgen_services): skip service status marks

Recent versions of systemctl seems to prefix a character representing
the status before the unit names.  Thus, in addition to $1, $2 may
also contain a service name.

Author: akinomyoga

bash_completion

@@ -2223,8 +2223,13 @@ _comp_compgen_services()
     local _generated=$({
         systemctl list-units --full --all ||
             systemctl list-unit-files
-    } 2>/dev/null |
-        _comp_awk '$1 ~ /\.service$/ { sub("\\.service$", "", $1); print $1 }')
+    } 2>/dev/null | _comp_awk '
+        # Example output from systemctl:
+        #   httpd.service       loaded    active   running  The Apache HTTP Server
+        # * iptables.service    not-found inactive dead     iptables.service
+        sub(/\.service$/, "", $1) { print $1; next }
+        sub(/\.service$/, "", $2) { print $2 }
+    ')
     _comp_compgen -a split -l -- "$_generated" && status=0
 
     if [[ -x /sbin/upstart-udev-bridge ]]; then