Fix typos, comments, style, optimize macros

Signed-off-by: Przemek Stekiel <przemyslaw.stekiel@mobica.com>
diff --git a/tests/suites/test_suite_psa_crypto.function b/tests/suites/test_suite_psa_crypto.function
index 34bb5e2..61ac74e 100644
--- a/tests/suites/test_suite_psa_crypto.function
+++ b/tests/suites/test_suite_psa_crypto.function
@@ -1519,7 +1519,8 @@
 
     if (PSA_KEY_TYPE_IS_DH(type) &&
         expected_export_status == PSA_ERROR_BUFFER_TOO_SMALL) {
-        export_size -= 8;
+        /* Simulate that buffer is too small, by decreasing its size by 1 byte. */
+        export_size -= 1;
     }
 
     if (PSA_KEY_TYPE_IS_DH(type) &&