Remove invalid comments in pk_can_do_ext()

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
diff --git a/tests/suites/test_suite_pk.function b/tests/suites/test_suite_pk.function
index 057a2e6..c7b514e 100644
--- a/tests/suites/test_suite_pk.function
+++ b/tests/suites/test_suite_pk.function
@@ -275,13 +275,9 @@
     TEST_EQUAL( mbedtls_pk_can_do_ext( &pk, alg_check ), result );
 
 exit:
-    /*
-     * Key attributes may have been returned by psa_get_key_attributes()
-     * thus reset them as required.
-     */
     psa_reset_key_attributes( &attributes );
     PSA_ASSERT( psa_destroy_key( key ) );
-    mbedtls_pk_free( &pk ); /* redundant except upon error */
+    mbedtls_pk_free( &pk );
     USE_PSA_DONE( );
 }
 /* END_CASE */