Update tests

Author: lucic71

tests/unit/out/refcount/empty_main.rs

@@ -24,6 +24,6 @@ pub fn main() {
     ::std::process::exit(main_0(::std::env::args().len() as i32, argv.as_pointer()));
 }
 fn main_0(_a0: i32, _a1: Ptr<Ptr<i8>>) -> i32 {
-    return 0;
+    0
 }
 pub fn __cpp2rust_init_globals() {}

tests/unit/out/unsafe/empty_main.rs

@@ -23,6 +23,6 @@ pub fn main() {
     }
 }
 unsafe fn main_0(mut _a0: i32, mut _a1: *mut *mut libc::c_char) -> i32 {
-    return 0;
+    0
 }
 pub unsafe fn __cpp2rust_init_globals() {}