Address comments in pull request #51084.

src/test/ui/issue-51022.rs

@@ -8,5 +8,5 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern: `main` function is not allowed to have lifetime parameters
 fn main<'a>() { }
+    //~^ ERROR `main` function is not allowed to have lifetime parameters [E0131]

src/test/ui/issue-51022.stderr

@@ -0,0 +1,9 @@
+error[E0131]: `main` function is not allowed to have lifetime parameters
+  --> $DIR/issue-51022.rs:11:8
+   |
+LL | fn main<'a>() { }
+   |        ^^^^ `main` cannot have lifetime parameters
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0131`.