libublk: fix visibility

1) remove pub for UblkQueueState

2) mark queue.process_ios() as pub(crate)

Signed-off-by: Ming Lei <tom.leiming@gmail.com>

src/io.rs

@@ -276,7 +276,7 @@ impl Drop for UblkDev {
 }
 
 #[derive(Debug, Clone, Default)]
-pub struct UblkQueueState {
+struct UblkQueueState {
     cmd_inflight: u32,
     state: u32,
 }
@@ -285,12 +285,6 @@ impl UblkQueueState {
     const UBLK_QUEUE_STOPPING: u32 = 1_u32 << 0;
     const UBLK_QUEUE_IDLE: u32 = 1_u32 << 1;
 
-    pub fn new() -> Self {
-        Self {
-            ..Default::default()
-        }
-    }
-
     #[inline(always)]
     fn queue_is_quiesced(&self) -> bool {
         self.cmd_inflight == 0
@@ -845,7 +839,7 @@ impl UblkQueue<'_> {
     /// provided, and target code can return UblkFatRes::BatchRes(batch) to
     /// cover each completed IO(tag, result) in io closure. Then, all these
     /// added IOs will be completed automatically.
-    pub fn process_ios<F>(&self, mut ops: F, to_wait: usize) -> Result<i32, UblkError>
+    pub(crate) fn process_ios<F>(&self, mut ops: F, to_wait: usize) -> Result<i32, UblkError>
     where
         F: FnMut(&UblkQueue, u16, &UblkIOCtx),
     {