Rollup merge of #101535 - est31:tidy_error_fix, r=Mark-Simulacrum

Fix error printing mistake in tidy

Fixes a small bug in the error printing code added by #100591 .

src/tools/tidy/src/features.rs

@@ -199,8 +199,7 @@ pub fn check(
         if channel != "nightly" && since == Version::CurrentPlaceholder {
             tidy_error!(
                 bad,
-                "The placeholder use of {kind} feature `{feature_name}` is not allowed on the {} channel",
-                version::VERSION_PLACEHOLDER
+                "The placeholder use of {kind} feature `{feature_name}` is not allowed on the {channel} channel",
             );
         }
     }