Update libloading to 0.7.3

Test: cd external/rust/crates && atest --host -c
Change-Id: I1a047668c589c6e149a693e9a8ac9e7e9ecbb325
diff --git a/tests/constants.rs b/tests/constants.rs
index ad910c4..6ae5a84 100644
--- a/tests/constants.rs
+++ b/tests/constants.rs
@@ -1,5 +1,5 @@
-extern crate libloading;
 extern crate libc;
+extern crate libloading;
 extern crate static_assertions;
 
 #[cfg(all(test, unix))]
diff --git a/tests/functions.rs b/tests/functions.rs
index eef41e6..795f0cf 100644
--- a/tests/functions.rs
+++ b/tests/functions.rs
@@ -148,7 +148,7 @@
 }
 
 #[test]
-// Something about i686-pc-windows-gnu, makes dll initialization code call abort when it is loaded
+// Something about i686-pc-windows-gnu, makes dll initialisation code call abort when it is loaded
 // and unloaded many times. So far it seems like an issue with mingw, not libloading, so ignoring
 // the target. Especially since it is very unlikely to be fixed given the state of support its
 // support.
@@ -193,7 +193,7 @@
     use libloading::os::windows::Library;
     make_helpers();
     unsafe {
-        // SAFE: well-known library without initializers is loaded.
+        // SAFE: well-known library without initialisers is loaded.
         let _lib = Library::new(LIBPATH).unwrap();
         let this = Library::this().expect("this library");
         // SAFE: functions are never called.