files: implement default support

rust/src/filecontainer.rs

@@ -28,7 +28,7 @@ pub const FILE_USE_DETECT:    u16 = BIT_U16!(13);
 
 
 // Generic file structure, so it can be used by different protocols
-#[derive(Debug)]
+#[derive(Debug, Default)]
 pub struct Files {
     pub files_ts: FileContainer,
     pub files_tc: FileContainer,
@@ -68,6 +68,13 @@ pub struct FileContainer {
     tail: * mut c_void,
 }
 
+impl Default for FileContainer {
+    fn default() -> Self { Self {
+        head: ptr::null_mut(),
+        tail: ptr::null_mut(),
+    }}
+}
+
 impl FileContainer {
     pub fn default() -> FileContainer {
         FileContainer { head:ptr::null_mut(), tail:ptr::null_mut() }