refactor: ubyte has From<usize>

pageserver/src/tenant/timeline.rs

@@ -862,7 +862,7 @@ impl Timeline {
             // S3 has a 5 GB limit on the size of one upload (without multi-part upload), and
             // we want to stay below that with a big margin.  The LSN distance determines how
             // much WAL the safekeepers need to store.
-            if distance >= self.get_checkpoint_distance().into()
+            if distance >= i128::from(self.get_checkpoint_distance())
                 || open_layer_size > self.get_checkpoint_distance()
                 || (distance > 0 && last_freeze_ts.elapsed() >= self.get_checkpoint_timeout())
             {

pageserver/src/walredo.rs

@@ -883,7 +883,7 @@ impl PostgresRedoManager {
             // into this buffer.
             let mut resultbuf = vec![0; BLCKSZ.into()];
             let mut nresult: usize = 0; // # of bytes read into 'resultbuf' so far
-            while nresult < BLCKSZ.into() {
+            while nresult < usize::from(BLCKSZ) {
                 // We do two things simultaneously: reading response from stdout
                 // and forward any logging information that the child writes to its stderr to the page server's log.
                 let n = loop {