[PATCH] Fix build error when disable nscd.

[Cooper Qu]

The error is as follows:
nss_module.c: In function 'module_load_nss_files':
nss_module.c:117:7: error: 'is_nscd' undeclared (first use in this function)
  117 |   if (is_nscd)
      |       ^~~~~~~
nss_module.c:117:7: note: each undeclared identifier is reported only once for each function it appears in
nss_module.c:119:51: error: 'nscd_init_cb' undeclared (first use in this function); did you mean 'nscd_init'?
  119 |       void (*cb) (size_t, struct traced_file *) = nscd_init_cb;
      |                                                   ^~~~~~~~~~~~
      |                                                   nscd_init
---
 nss/nss_module.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/nss/nss_module.c b/nss/nss_module.c
index 7b42c585a4..b42f37953c 100644
--- a/nss/nss_module.c
+++ b/nss/nss_module.c
@@ -114,6 +114,7 @@ static const function_name nss_function_name_array[] =
 static bool
 module_load_nss_files (struct nss_module *module)
 {
+# ifdef USE_NSCD
   if (is_nscd)
     {
       void (*cb) (size_t, struct traced_file *) = nscd_init_cb;
@@ -122,6 +123,7 @@ module_load_nss_files (struct nss_module *module)
 #  endif
       _nss_files_init (cb);
     }
+#endif
 
   /* Initialize the function pointers, following the double-checked
      locking idiom.  */
-- 
2.26.2