Correct kerl cleanup call in install callback

Fixes #280

bin/install

@@ -30,7 +30,7 @@ install_erlang() {
     # "You can activate this installation running the following command:"
     # that doesn't apply is hidden
     $(kerl_path) install "$build_name" "$ASDF_INSTALL_PATH" >/dev/null 2>&1
-    $(kerl_path) cleanup "$ASDF_INSTALL_VERSION"
+    $(kerl_path) cleanup "$build_name"
 
     link_app_executables "$ASDF_INSTALL_PATH"
 }