Improve bash completion for docker volume ls -f dangling

Signed-off-by: Harald Albers <github@albersweb.de>
Upstream-commit: a381efcf39ef7f82b1496a4bbaf42df096d91bc5
Component: engine

components/engine/contrib/completion/bash/docker

@@ -2002,7 +2002,8 @@ _docker_volume_inspect() {
 _docker_volume_ls() {
 	case "$prev" in
 		--filter|-f)
-			COMPREPLY=( $( compgen -W "dangling" -- "$cur" ) )
+			COMPREPLY=( $( compgen -S = -W "dangling" -- "$cur" ) )
+			__docker_nospace
 			return
 			;;
 	esac