ptsname_r: Fix test failure on Solaris

[Bruno Haible]

The ptsname_r test fails on Solaris 11 OpenIndiana and Solaris 11 OmniOS:

  ../../gltests/test-ptsname_r.c:167: assertion 'result == 0' failed
  FAIL test-ptsname_r (exit status: 262)

This patch fixes it, by removing the test on the major number of the
device. This major number is (according to 'ls -l /dev/pts/'):
  - 24 on Solaris 10,
  - 221 on Solaris 11.3,
  - 195 on Solaris OpenIndiana,
  - 180 on Solaris OmniOS.


2020-12-31  Bruno Haible  <bruno@clisp.org>

        ptsname_r: Fix test failure on Solaris.
        * lib/ptsname_r.c (__ptsname_r) [__sun]: Don't test the major number of
        the device.

diff --git a/lib/ptsname_r.c b/lib/ptsname_r.c
index 0008b95..c2fc65f 100644
--- a/lib/ptsname_r.c
+++ b/lib/ptsname_r.c
@@ -97,7 +97,7 @@ __ptsname_r (int fd, char *buf, size_t buflen)
 # if defined __sun /* Solaris */
   if (fstat (fd, &st) < 0)
     return errno;
-  if (!(S_ISCHR (st.st_mode) && major (st.st_rdev) == 0))
+  if (!S_ISCHR (st.st_mode))
     {
       errno = ENOTTY;
       return errno;