fix clippy warnings

src/uu/factor/src/factor.rs

@@ -163,6 +163,7 @@ pub fn factor(mut n: u64) -> Factors {
 
     let (factors, n) = table::factor(n, factors);
 
+    #[allow(clippy::let_and_return)]
     let r = if n < (1 << 32) {
         _factor::<Montgomery<u32>>(n, factors)
     } else {
@@ -280,6 +281,6 @@ impl std::ops::BitXor<Exponent> for Factors {
         }
 
         debug_assert_eq!(r.product(), self.product().pow(rhs.into()));
-        return r;
+        r
     }
 }

src/uu/ls/src/ls.rs

@@ -1413,11 +1413,11 @@ fn get_block_size(md: &Metadata, config: &Config) -> u64 {
     {
         // hard-coded for now - enabling setting this remains a TODO
         let ls_block_size = 1024;
-        return match config.size_format {
+        match config.size_format {
             SizeFormat::Binary => md.blocks() * 512,
             SizeFormat::Decimal => md.blocks() * 512,
             SizeFormat::Bytes => md.blocks() * 512 / ls_block_size,
-        };
+        }
     }
 
     #[cfg(not(unix))]

src/uu/test/src/parser.rs

@@ -121,6 +121,8 @@ impl Parser {
     /// Test if the next token in the stream is a BOOLOP (-a or -o), without
     /// removing the token from the stream.
     fn peek_is_boolop(&mut self) -> bool {
+        // TODO: change to `matches!(self.peek(), Symbol::BoolOp(_))` once MSRV is 1.42
+        // #[allow(clippy::match_like_matches_macro)] // needs MSRV 1.43
         if let Symbol::BoolOp(_) = self.peek() {
             true
         } else {