fix clippy warnings

Author: Serban Iorga

src/bytes.rs

@@ -359,7 +359,7 @@ mod tests {
         fn read_slice(&self, buf: &mut [u8], addr: usize) -> Result<(), Self::E> {
             self.validate_slice_op(buf, addr)?;
 
-            buf.copy_from_slice(&self.container[addr..=buf.len() - 1]);
+            buf.copy_from_slice(&self.container[addr..buf.len()]);
 
             Ok(())
         }

src/mmap.rs

@@ -372,17 +372,15 @@ impl GuestMemoryRegion for GuestRegionMmap {
 /// Represents the entire physical memory of the guest by tracking all its memory regions.
 /// Each region is an instance of `GuestRegionMmap`, being backed by a mapping in the
 /// virtual address space of the calling process.
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, Default)]
 pub struct GuestMemoryMmap {
     regions: Vec<Arc<GuestRegionMmap>>,
 }
 
 impl GuestMemoryMmap {
     /// Creates an empty `GuestMemoryMmap` instance.
     pub fn new() -> Self {
-        GuestMemoryMmap {
-            regions: Vec::new(),
-        }
+        Self::default()
     }
 
     /// Creates a container and allocates anonymous memory for guest memory regions.

src/mmap_unix.rs

@@ -271,10 +271,10 @@ mod tests {
     // distinctive value when the error is represented by another variant.
     impl Error {
         pub fn raw_os_error(&self) -> i32 {
-            return match self {
+            match self {
                 Error::Mmap(e) => e.raw_os_error().unwrap(),
                 _ => std::i32::MIN,
-            };
+            }
         }
     }
 

src/volatile_memory.rs

@@ -1084,8 +1084,8 @@ mod tests {
             format!(
                 "{}",
                 Error::TooBig {
-                    nelements: 100000,
-                    size: 1000000000
+                    nelements: 100_000,
+                    size: 1_000_000_000
                 }
             ),
             "100000 elements of size 1000000000 would overflow a usize"
@@ -1498,8 +1498,8 @@ mod tests {
         let a_ref = &mut a[..];
         let a_slice = a_ref.get_slice(0, a_ref.len()).unwrap();
         let a_array_ref: VolatileArrayRef<u8> = a_slice.into();
-        for i in 0..a_vec.len() {
-            assert_eq!(a_array_ref.load(i), a_vec[i]);
+        for (i, entry) in a_vec.iter().enumerate() {
+            assert_eq!(&a_array_ref.load(i), entry);
         }
     }