[libc][Obvious] Fix typo in strnlen_test.cpp.

GitOrigin-RevId: a513be490080ce7b974c5411a9de38e118c25991
diff --git a/test/src/string/strnlen_test.cpp b/test/src/string/strnlen_test.cpp
index 9d8616b..b15ec2f 100644
--- a/test/src/string/strnlen_test.cpp
+++ b/test/src/string/strnlen_test.cpp
@@ -1,4 +1,4 @@
-//===-- Unittests for strnlen----------------------------------------------===//
+//===-- Unittests for strnlen ---------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.