Fix free before pointers initialised

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/tests/suites/test_suite_md.function b/tests/suites/test_suite_md.function
index 75087e7..03b1864 100644
--- a/tests/suites/test_suite_md.function
+++ b/tests/suites/test_suite_md.function
@@ -386,7 +386,6 @@
 void md_psa_dynamic_dispatch(int md_type, int pre_psa_ret, int post_psa_engine)
 {
     const mbedtls_md_info_t *md_info = mbedtls_md_info_from_type(md_type);
-    TEST_ASSERT(md_info != NULL);
     mbedtls_md_context_t ctx1, ctx2;
 
     /* Intentionally no PSA init here! (Will be done later.) */
@@ -394,6 +393,8 @@
     mbedtls_md_init(&ctx1);
     mbedtls_md_init(&ctx2);
 
+    TEST_ASSERT(md_info != NULL);
+
     /* Before PSA crypto init */
     TEST_EQUAL(pre_psa_ret, mbedtls_md_setup(&ctx1, md_info, 0));
     TEST_EQUAL(pre_psa_ret, mbedtls_md_setup(&ctx2, md_info, 0));