Fix error in fuzztest for fixed size arrays
diff --git a/tests/fuzztest/validation.c b/tests/fuzztest/validation.c
index 49aa82c..939bf9e 100644
--- a/tests/fuzztest/validation.c
+++ b/tests/fuzztest/validation.c
@@ -61,7 +61,7 @@
     if (!iter->pData)
     {
         /* Nothing allocated */
-        if (iter->pSize)
+        if (PB_HTYPE(iter->type) == PB_HTYPE_REPEATED && iter->pSize != &iter->array_size)
         {
             assert(*(pb_size_t*)iter->pSize == 0);
         }