envsetup: fix lineagegerrit push for zsh

- fixes:
  error: src refspec HEADefs/for/lineage-18.1 does not match any
  In zsh, :r is a modifier.

Change-Id: Ie6a2a079a96f13c8eb6732a796bab2c2700d7276

build/envsetup.sh

@@ -573,7 +573,7 @@ EOF
             esac
             shift
             git push $@ ssh://$user@$review:29418/$project \
-                $local_branch:refs/for/$remote_branch || return 1
+                ${local_branch}:refs/for/$remote_branch || return 1
             ;;
         changes|for)
             if [ "$FUNCNAME" = "lineagegerrit" ]; then