[glibc/maskray/grte] Describe borg-pwd better, remove dead code.

[glibc/maskray/grte] Describe borg-pwd better, remove dead code.

[Fangrui Song]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=aeca36379f1bb893a2e3fb32aa1b7a9c2b869e64

commit aeca36379f1bb893a2e3fb32aa1b7a9c2b869e64
Author: Stan Shebs <stanshebs@google.com>
Date:   Fri Aug 21 14:50:53 2015 -0700

    Describe borg-pwd better, remove dead code.

Diff:
---
 nss/nss_borg/borg-pwd.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/nss/nss_borg/borg-pwd.c b/nss/nss_borg/borg-pwd.c
index afa696c6fd..c4ff035984 100644
--- a/nss/nss_borg/borg-pwd.c
+++ b/nss/nss_borg/borg-pwd.c
@@ -2,6 +2,8 @@
 // Author: Paul Menage
 
 // An NSS module that extends local user account lookup to the file /etc/passwd.borg
+// (Despite the suggestive name, passwd.borg is just a second file in the standard
+// passwd format, separated for various reasons. -sts 2015)
 
 #include <stdio.h>
 #include <pwd.h>
@@ -10,17 +12,10 @@
 #include <errno.h>
 #include <string.h>
 
-#ifdef NSSBORG_STANDALONE
-#include <pthread.h>
-static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
-#define NSSBORG_LOCK  pthread_mutex_lock(&mutex)
-#define NSSBORG_UNLOCK pthread_mutex_unlock(&mutex)
-#else
 #include <libc-lock.h>
 __libc_lock_define_initialized (static, lock)
 #define NSSBORG_LOCK  __libc_lock_lock (lock)
 #define NSSBORG_UNLOCK  __libc_lock_unlock (lock);
-#endif
 
 static FILE *f;