Fix build: pthread_mutex/pthread_detach.

Change-Id: I9c7b6297d3bf3ab8004d05d44cc4c95159315c9e
diff --git a/libc/bionic/pthread_detach.cpp b/libc/bionic/pthread_detach.cpp
index 0712d0d..7ae5eb4 100644
--- a/libc/bionic/pthread_detach.cpp
+++ b/libc/bionic/pthread_detach.cpp
@@ -44,9 +44,9 @@
     }
     switch (old_state) {
       case THREAD_NOT_JOINED: return 0;
-      case THREAD_JOINED:     return 0; // Already being joined; silently do nothing, like glibc.
+      case THREAD_JOINED:     return 0;  // Already being joined; silently do nothing, like glibc.
       case THREAD_DETACHED:   return THREAD_DETACHED;
-      case THREAD_EXITED_NOT_JOINED:  // Call pthread_join out of scope of pthread_accessor.
+      case THREAD_EXITED_NOT_JOINED: break;  // Call pthread_join out of scope of pthread_accessor.
     }
   }