extensions BUGFIX reflect change from commit 01cdea196

The content member is not zero sized, so its 1 byte must be reflected
when initializing its content.
diff --git a/src/resolve.c b/src/resolve.c
index d481388..b7995eb 100644
--- a/src/resolve.c
+++ b/src/resolve.c
@@ -5038,9 +5038,10 @@
             /* nothing change */
             break;
         case LYEXT_COMPLEX:
-            tmp_ext = realloc(*ext, sizeof **ext + ((struct lyext_plugin_complex*)e->plugin)->instance_size);
+            tmp_ext = realloc(*ext, ((struct lyext_plugin_complex*)e->plugin)->instance_size);
             LY_CHECK_ERR_GOTO(!tmp_ext, LOGMEM(ctx), error);
-            memset((char *)tmp_ext + sizeof **ext, 0, ((struct lyext_plugin_complex*)e->plugin)->instance_size - sizeof **ext);
+            memset((char *)tmp_ext + offsetof(struct lys_ext_instance_complex, content), 0,
+                   ((struct lyext_plugin_complex*)e->plugin)->instance_size - offsetof(struct lys_ext_instance_complex, content));
             (*ext) = tmp_ext;
             ((struct lys_ext_instance_complex*)(*ext))->substmt = ((struct lyext_plugin_complex*)e->plugin)->substmt;
             if (info->data.yang) {