Fix treehash.yml (#1202)

Author: lgoettgens

.github/workflows/treehash.yml

@@ -36,9 +36,9 @@ jobs:
             using GAP_pkg_juliainterface_jll
             jll = GAP_pkg_juliainterface_jll.find_artifact_dir()
             jll_hash = GitTools.tree_hash(joinpath(jll, "src"))
-            bundled = joinpath(@__DIR__, "..", "pkg", "JuliaInterface")
+            bundled = joinpath(@__DIR__, "pkg", "JuliaInterface")
             bundled_hash = GitTools.tree_hash(joinpath(bundled, "src"))
-            jll_hash == bundled_hash || error("tree hash is $src_hash, but JLL uses $jll_hash")
+            jll_hash == bundled_hash || error("tree hash is $bundled_hash, but JLL uses $jll_hash")
             '
       # next verify that GAP.jl still runs when forced to rebuild juliainterface;
       # as a side effect this also reduce code coverage fluctuation when