tracing: remove duplicated event macro pattern (#1352)

The following two patterns for the `event!()` are identical to each
other, and the second one swapped the order of `$lvl` and `parent:
$parent` which I don't think is correct. 
```rust
    (parent: $parent:expr, $lvl:expr, { $($fields:tt)* }, $($arg:tt)+ ) => (
        $crate::event!(
            target: module_path!(),
            parent: $parent,
            $lvl,
            { message = format_args!($($arg)+), $($fields)* }
        )
    );
    (parent: $parent:expr, $lvl:expr, { $($fields:tt)* }, $($arg:tt)+ ) => (
        $crate::event!(
            target: module_path!(),
            $lvl,
            parent: $parent,
            { message = format_args!($($arg)+), $($fields)* }
        )
    );
```

I found the duplicated via
[macro_railraod](https://github.com/lukaslueg/macro_railroad). Here is
the diagram: 

![image](https://user-images.githubusercontent.com/3369694/114296705-47ec8700-9adf-11eb-971f-f485329d0339.png)
This commit is contained in:
Folyd 2021-04-14 01:02:38 +08:00 committed by Eliza Weisman
parent 07af5f8fd8
commit 3d65a48526

View File

@ -684,14 +684,6 @@ macro_rules! event {
{ message = format_args!($($arg)+), $($fields)* }
)
);
(parent: $parent:expr, $lvl:expr, { $($fields:tt)* }, $($arg:tt)+ ) => (
$crate::event!(
target: module_path!(),
$lvl,
parent: $parent,
{ message = format_args!($($arg)+), $($fields)* }
)
);
(parent: $parent:expr, $lvl:expr, $($k:ident).+ = $($field:tt)*) => (
$crate::event!(
target: module_path!(),