Clean up compilation warnings
diff --git a/library/pkparse.c b/library/pkparse.c
index bddcf5d..275429e 100644
--- a/library/pkparse.c
+++ b/library/pkparse.c
@@ -1181,6 +1181,7 @@
         return( ret );
 #endif /* MBEDTLS_PKCS12_C || MBEDTLS_PKCS5_C */
 #else
+    ((void) ret);
     ((void) pwd);
     ((void) pwdlen);
 #endif /* MBEDTLS_PEM_PARSE_C */