unistd: Fix portability warnings

[Bruno Haible]

This patch fixes some missing update from when the modules 'fchownat'
and 'unlinkat' were split off from module 'openat' in 2011.


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

        unistd: Fix portability warnings.
        * lib/unistd.in.h (fchownat, unlinkat): Fix module name in warning.

diff --git a/lib/unistd.in.h b/lib/unistd.in.h
index d43556a..3f3b995 100644
--- a/lib/unistd.in.h
+++ b/lib/unistd.in.h
@@ -978,7 +978,7 @@ _GL_CXXALIASWARN (fchownat);
 # undef fchownat
 # if HAVE_RAW_DECL_FCHOWNAT
 _GL_WARN_ON_USE (fchownat, "fchownat is not portable - "
-                 "use gnulib module openat for portability");
+                 "use gnulib module fchownat for portability");
 # endif
 #endif
 
@@ -2219,7 +2219,7 @@ _GL_CXXALIASWARN (unlinkat);
 # undef unlinkat
 # if HAVE_RAW_DECL_UNLINKAT
 _GL_WARN_ON_USE (unlinkat, "unlinkat is not portable - "
-                 "use gnulib module openat for portability");
+                 "use gnulib module unlinkat for portability");
 # endif
 #endif