tar: switch to gnulib fdutimensat module

* gnulib.modules: Add fdutimensat.
* src/common.h (fd_utimensat): Remove decl.
* src/extract.c (set_stat): Call fdutimensat, not fd_utimensat.
* src/misc.c (set_file_atime): Likewise.
(fd_utimensat): Remove.

gnulib.modules

@@ -13,6 +13,7 @@ error
 exclude
 exitfail
 fdopendir
+fdutimensat
 fileblocks
 fnmatch-gnu
 fseeko

src/common.h

@@ -612,8 +612,6 @@ bool maybe_backup_file (const char *file_name, bool this_is_the_archive);
 void undo_last_backup (void);
 
 int deref_stat (bool deref, char const *name, struct stat *buf);
-int fd_utimensat (int fd, int parentfd, char const *file,
-		  struct timespec const ts[2], int atflag);
 
 extern int chdir_current;
 int chdir_arg (char const *dir);

src/extract.c

@@ -324,7 +324,7 @@ set_stat (char const *file_name,
 	ts[0].tv_nsec = UTIME_OMIT;
       ts[1] = st->mtime;
 
-      if (fd_utimensat (fd, AT_FDCWD, file_name, ts, atflag) == 0)
+      if (fdutimensat (fd, AT_FDCWD, file_name, ts, atflag) == 0)
 	{
 	  if (incremental_option)
 	    check_time (file_name, ts[0]);

src/misc.c

@@ -613,21 +613,6 @@ deref_stat (bool deref, char const *name, struct stat *buf)
   return deref ? stat (name, buf) : lstat (name, buf);
 }
 
-/* Use futimens if possible, utimensat otherwise.  */
-int
-fd_utimensat (int fd, int parentfd, char const *file,
-	      struct timespec const ts[2], int atflag)
-{
-  if (0 <= fd)
-    {
-      int result = futimens (fd, ts);
-      if (! (result < 0 && errno == ENOSYS))
-	return result;
-    }
-
-  return utimensat (parentfd, file, ts, atflag);
-}
-
 /* Set FD's (i.e., assuming the working directory is PARENTFD, FILE's)
    access time to ATIME.  ATFLAG controls symbolic-link following, in
    the style of openat.  */
@@ -638,7 +623,7 @@ set_file_atime (int fd, int parentfd, char const *file, struct timespec atime,
   struct timespec ts[2];
   ts[0] = atime;
   ts[1].tv_nsec = UTIME_OMIT;
-  return fd_utimensat (fd, parentfd, file, ts, atflag);
+  return fdutimensat (fd, parentfd, file, ts, atflag);
 }
 
 /* A description of a working directory.  */