tests: psa: Use PSA_KEY_LIFETIME_IS_VOLATILE where it should

Signed-off-by: Ronald Cron <ronald.cron@arm.com>
diff --git a/tests/suites/test_suite_psa_crypto.function b/tests/suites/test_suite_psa_crypto.function
index 9b113b4..204e36e 100644
--- a/tests/suites/test_suite_psa_crypto.function
+++ b/tests/suites/test_suite_psa_crypto.function
@@ -112,7 +112,7 @@
 {
     /* At the moment, anything that isn't a built-in lifetime is either
      * a secure element or unassigned. */
-    return( lifetime != PSA_KEY_LIFETIME_VOLATILE &&
+    return( ( ! PSA_KEY_LIFETIME_IS_VOLATILE( lifetime ) ) &&
             lifetime != PSA_KEY_LIFETIME_PERSISTENT );
 }
 #else
@@ -245,7 +245,7 @@
     bits = psa_get_key_bits( &attributes );
 
     /* Persistence */
-    if( lifetime == PSA_KEY_LIFETIME_VOLATILE )
+    if( PSA_KEY_LIFETIME_IS_VOLATILE( lifetime ) )
     {
         TEST_ASSERT(
             ( PSA_KEY_ID_VOLATILE_MIN <=