Bash completion for `docker service ps` completes only one service

Signed-off-by: Harald Albers <github@albersweb.de>

contrib/completion/bash/docker

@@ -2928,7 +2928,10 @@ _docker_service_ps() {
 			COMPREPLY=( $( compgen -W "--filter -f --help --no-resolve --no-trunc --quiet -q" -- "$cur" ) )
 			;;
 		*)
-			__docker_complete_services
+			local counter=$(__docker_pos_first_nonflag '--filter|-f')
+			if [ $cword -eq $counter ]; then
+				__docker_complete_services
+			fi
 			;;
 	esac
 }