Merge #775

775: Fix test warnings r=asomers a=SanchayanMaity

Author: bors[bot]

nix-test/build.rs

@@ -13,7 +13,7 @@ pub fn main() {
         "UNKNOWN"
     };
 
-    gcc::Config::new()
+    gcc::Build::new()
         .file("src/const.c")
         .file("src/sizes.c")
         .define(os, None)

test/sys/test_aio.rs

@@ -13,7 +13,7 @@ use std::{thread, time};
 use tempfile::tempfile;
 
 // Helper that polls an AioCb for completion or error
-fn poll_aio(mut aiocb: &mut AioCb) -> Result<()> {
+fn poll_aio(aiocb: &mut AioCb) -> Result<()> {
     loop {
         let err = aiocb.error();
         if err != Err(Error::from(Errno::EINPROGRESS)) { return err; };