Clippy fixes and other minor cleanup

av1an-core/src/context.rs

@@ -169,9 +169,7 @@ impl Av1anContext {
               for arg in vspipe_args {
                 command.args(["-a", &arg]);
               }
-              command.spawn()
-                .unwrap()
-                .wait()
+              command.status()
                 .unwrap()
             })
           })

av1an-core/src/parse.rs

@@ -185,7 +185,7 @@ pub unsafe fn parse_aom_vpx_frames_sse41(s: &[u8]) -> Option<u64> {
   let mult = _mm_set_epi16(0, 0, 0, 0, 1, 10000, 1, 10000);
   chunk = _mm_madd_epi16(chunk, mult);
 
-  let chunk = transmute::<_, [u64; 2]>(chunk);
+  let chunk = transmute::<__m128i, [u64; 2]>(chunk);
 
   Some(((chunk[0] & 0xffff_ffff) * 100_000_000) + (chunk[0] >> 32))
 }

av1an-core/src/util.rs

@@ -39,7 +39,7 @@ macro_rules! inplace_vec {
         idx += 1;
       )*
 
-      mem::transmute::<_, Vec<Cow<_>>>(v)
+      mem::transmute::<Vec<MaybeUninit<Cow<_>>>, Vec<Cow<_>>>(v)
     }
   }};
 }

av1an-core/src/vmaf.rs

@@ -2,7 +2,6 @@ use std::cmp::Ordering;
 use std::ffi::OsStr;
 use std::path::Path;
 use std::process::{Command, Stdio};
-use std::usize;
 
 use anyhow::{anyhow, Context};
 use plotters::prelude::*;
@@ -260,7 +259,7 @@ pub fn run_vmaf(
   cmd.stderr(Stdio::piped());
   cmd.stdout(Stdio::null());
 
-  let output = cmd.spawn().unwrap().wait_with_output().unwrap();
+  let output = cmd.output().unwrap();
 
   if !output.status.success() {
     return Err(Box::new(EncoderCrash {