flt2dec: fix some clippy lints

Author: hkBst

library/core/src/num/flt2dec/mod.rs

@@ -150,17 +150,13 @@ pub fn round_up(d: &mut [u8]) -> Option<u8> {
         Some(i) => {
             // d[i+1..n] is all nines
             d[i] += 1;
-            for j in i + 1..d.len() {
-                d[j] = b'0';
-            }
+            d.iter_mut().skip(i + 1).for_each(|c| *c = b'0');
             None
         }
-        None if d.len() > 0 => {
+        None if !d.is_empty() => {
             // 999..999 rounds to 1000..000 with an increased exponent
             d[0] = b'1';
-            for j in 1..d.len() {
-                d[j] = b'0';
-            }
+            d.iter_mut().skip(1).for_each(|c| *c = b'0');
             Some(b'0')
         }
         None => {