Remove code that is useless now that components run in a subshell

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index 8334ade..f657da7 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -271,10 +271,6 @@
 # remove built files as well as the cmake cache/config
 cleanup()
 {
-    if [ -n "${MBEDTLS_ROOT_DIR+set}" ]; then
-        cd "$MBEDTLS_ROOT_DIR"
-    fi
-
     command make clean
 
     # Remove CMake artefacts
@@ -2792,7 +2788,6 @@
     rm ssl-opt.err
     cd "$MBEDTLS_ROOT_DIR"
     rm -rf "$OUT_OF_SOURCE_DIR"
-    unset MBEDTLS_ROOT_DIR
 }
 
 component_test_cmake_as_subdirectory () {