gh-127614: Correctly check for ttyname_r() in configure (#128503)

PR #14868 replaced the ttyname() call with ttyname_r(), but the old
check remained.

Author: erlend-aasland

Modules/clinic/posixmodule.c.h

@@ -3347,7 +3347,7 @@ os_access_impl(PyObject *module, path_t *path, int mode, int dir_fd,
 #endif
 
 
-#ifdef HAVE_TTYNAME
+#ifdef HAVE_TTYNAME_R
 /*[clinic input]
 os.ttyname
 

Modules/posixmodule.c

@@ -5152,7 +5152,7 @@ AC_CHECK_FUNCS([ \
   sigfillset siginterrupt sigpending sigrelse sigtimedwait sigwait \
   sigwaitinfo snprintf splice strftime strlcpy strsignal symlinkat sync \
   sysconf tcgetpgrp tcsetpgrp tempnam timegm times tmpfile \
-  tmpnam tmpnam_r truncate ttyname umask uname unlinkat unlockpt utimensat utimes vfork \
+  tmpnam tmpnam_r truncate ttyname_r umask uname unlinkat unlockpt utimensat utimes vfork \
   wait wait3 wait4 waitid waitpid wcscoll wcsftime wcsxfrm wmemcmp writev \
 ])
 

configure

@@ -1506,8 +1506,8 @@
 /* Define to 1 if you have the 'truncate' function. */
 #undef HAVE_TRUNCATE
 
-/* Define to 1 if you have the 'ttyname' function. */
-#undef HAVE_TTYNAME
+/* Define to 1 if you have the 'ttyname_r' function. */
+#undef HAVE_TTYNAME_R
 
 /* Define to 1 if you don't have 'tm_zone' but do have the external array
    'tzname'. */