Update gnulib

This updates gnulib to a relatively recent commit.  Most of this was
done by the gnulib import script; the only change I made was to
update-gnulib.sh.

Tested on x86-64 Fedora 34.  I also did a mingw cross build.

gnulib/import/getrandom.c

@@ -1,18 +1,18 @@
 /* Obtain a series of random bytes.
 
-   Copyright 2020-2021 Free Software Foundation, Inc.
+   Copyright 2020-2022 Free Software Foundation, Inc.
 
-   This program is free software: you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 3 of the License, or
-   (at your option) any later version.
+   This file is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of the
+   License, or (at your option) any later version.
 
-   This program is distributed in the hope that it will be useful,
+   This file is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-   GNU General Public License for more details.
+   GNU Lesser General Public License for more details.
 
-   You should have received a copy of the GNU General Public License
+   You should have received a copy of the GNU Lesser General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
 
 /* Written by Paul Eggert.  */
@@ -178,7 +178,11 @@ getrandom (void *buffer, size_t length, unsigned int flags)
                     + (flags & GRND_NONBLOCK ? O_NONBLOCK : 0));
       fd = open (randdevice[devrandom], oflags);
       if (fd < 0)
-        return fd;
+        {
+          if (errno == ENOENT || errno == ENOTDIR)
+            errno = ENOSYS;
+          return -1;
+        }
       randfd[devrandom] = fd;
     }