[LangRef] Fix mistake in example (#84849)

Author: vitalybuka

llvm/docs/LangRef.rst

@@ -27553,12 +27553,12 @@ in example below:
 .. code-block:: text
 
     %cond = call i1 @llvm.experimental.widenable.condition()
-    br i1 %cond, label %solution_1, label %solution_2
+    br i1 %cond, label %fast_path, label %slow_path
 
-  label %fast_path:
+  fast_path:
     ; Apply memory-consuming but fast solution for a task.
 
-  label %slow_path:
+  slow_path:
     ; Cheap in memory but slow solution.
 
 Whether the result of intrinsic's call is `true` or `false`,