uvcgadget: silence a maybe-uninitialized warning

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/7875>

subprojects/gst-plugins-bad/sys/uvcgadget/configfs.c

@@ -769,7 +769,7 @@ configfs_parse_streaming_header (const char *path,
   struct dirent **entries;
   unsigned int i;
   int n_entries;
-  int ret;
+  int ret = 0;
 
   /* Find all entries corresponding to a format and parse them. */
   n_entries = scandir (path, &entries, format_filter, alphasort);