lint: Resolve the easier clippy lints

Hopefully the changes are self-explanatory and uncontroversial. This
eliminates much of the noise from `cargo clippy` and, for my purposes,
gives me a reasonable way to use it as a tool when writing and reviewing
code.

Here is the Clippy invocation I was using:

    cargo +nightly clippy -- -W clippy::correctness -A renamed_and_removed_lints -Aclippy::{blacklisted_name,borrowed_box,cast_lossless,cast_ptr_alignment,enum_variant_names,identity_op,if_same_then_else,mut_from_ref,needless_pass_by_value,new_without_default,new_without_default_derive,or_fun_call,ptr_arg,should_implement_trait,single_match,too_many_arguments,trivially_copy_pass_by_ref,unreadable_literal,unsafe_vector_initialization,useless_transmute}

TEST=cargo check --features wl-dmabuf,gpu,usb-emulation
TEST=boot linux

Change-Id: I55eb1b4a72beb2f762480e3333a921909314a0a2
Reviewed-on: https://chromium-review.googlesource.com/1356911
Commit-Ready: David Tolnay <dtolnay@chromium.org>
Tested-by: David Tolnay <dtolnay@chromium.org>
Reviewed-by: Dylan Reid <dgreid@chromium.org>

1 files changed, 2 insertions, 4 deletions

diff --git a/src/main.rs b/src/main.rs
index 75ad172..2f0320b 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -137,7 +137,7 @@ fn wait_all_children() -> bool {
     }
 
     // If we've made it to this point, not all of the children have exited.
-    return false;
+    false
 }
 
 fn set_argument(cfg: &mut Config, name: &str, value: Option<&str>) -> argument::Result<()> {
@@ -215,7 +215,7 @@ fn set_argument(cfg: &mut Config, name: &str, value: Option<&str>) -> argument::
                 }
                 cfg.params.push(format!(
                     "root=/dev/vd{} ro",
-                    char::from('a' as u8 + cfg.disks.len() as u8)
+                    char::from(b'a' + cfg.disks.len() as u8)
                 ));
             }
             cfg.disks.push(DiskOption {
@@ -628,12 +628,10 @@ fn create_qcow2(mut args: std::env::Args) -> std::result::Result<(), ()> {
         .open(&file_path)
         .map_err(|e| {
             error!("Failed opening qcow file at '{}': {:?}", file_path, e);
-            ()
         })?;
 
     QcowFile::new(file, size).map_err(|e| {
         error!("Failed to create qcow file at '{}': {:?}", file_path, e);
-        ()
     })?;
 
     Ok(())