Fix new warning with rust 1.21

Mutable references being declared mutable themselves is unnecessary and
now generates a warning.

Change-Id: I29c7652fb86e17a8eda21efc728dd09b726c304f
Signed-off-by: Dylan Reid <dgreid@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/717733
Reviewed-by: Stephen Barber <smbarber@chromium.org>
Reviewed-by: Zach Reizner <zachr@chromium.org>

3 files changed, 3 insertions, 3 deletions

diff --git a/net_util/src/lib.rs b/net_util/src/lib.rs
index 5c54687..76de2ef 100644
--- a/net_util/src/lib.rs
+++ b/net_util/src/lib.rs
@@ -92,7 +92,7 @@ impl Tap {
         unsafe {
             let ifrn_name = ifreq.ifr_ifrn.ifrn_name.as_mut();
             let ifru_flags = ifreq.ifr_ifru.ifru_flags.as_mut();
-            let mut name_slice = &mut ifrn_name[..TUNTAP_DEV_FORMAT.len()];
+            let name_slice = &mut ifrn_name[..TUNTAP_DEV_FORMAT.len()];
             name_slice.copy_from_slice(TUNTAP_DEV_FORMAT);
             *ifru_flags = (net_sys::IFF_TAP | net_sys::IFF_NO_PI | net_sys::IFF_VNET_HDR) as
                           c_short;
diff --git a/sys_util/src/mmap.rs b/sys_util/src/mmap.rs
index 13526d5..1d9ac9e 100644
--- a/sys_util/src/mmap.rs
+++ b/sys_util/src/mmap.rs
@@ -251,7 +251,7 @@ impl MemoryMapping {
             // It is safe to overwrite the volatile memory.  Acessing the guest
             // memory as a mutable slice is OK because nothing assumes another
             // thread won't change what is loaded.
-            let mut dst = &mut self.as_mut_slice()[mem_offset..mem_end];
+            let dst = &mut self.as_mut_slice()[mem_offset..mem_end];
             src.read_exact(dst).map_err(Error::ReadFromSource)?;
         }
         Ok(())
diff --git a/x86_64/src/regs.rs b/x86_64/src/regs.rs
index 1be0adf..cfe6de3 100644
--- a/x86_64/src/regs.rs
+++ b/x86_64/src/regs.rs
@@ -104,7 +104,7 @@ pub fn setup_msrs(vcpu: &kvm::Vcpu) -> Result<()> {
     let vec_size_bytes = mem::size_of::<kvm_msrs>() +
                          (entry_vec.len() * mem::size_of::<kvm_msr_entry>());
     let vec: Vec<u8> = Vec::with_capacity(vec_size_bytes);
-    let mut msrs: &mut kvm_msrs = unsafe {
+    let msrs: &mut kvm_msrs = unsafe {
         // Converting the vector's memory to a struct is unsafe.  Carefully using the read-only
         // vector to size and set the members ensures no out-of-bounds erros below.
         &mut *(vec.as_ptr() as *mut kvm_msrs)