tree-wide: Some glnx_fstatat_allow_noent() porting

The new API is definitely nicer.

Closes: #1180
Approved by: jlebon

src/libotutil/ot-fs-utils.c

@@ -104,27 +104,6 @@ ot_ensure_unlinked_at (int dfd,
   return TRUE;
 }
 
-gboolean
-ot_query_exists_at (int dfd, const char *path,
-                    gboolean *out_exists,
-                    GError **error)
-{
-  struct stat stbuf;
-  gboolean ret_exists;
-
-  if (fstatat (dfd, path, &stbuf, AT_SYMLINK_NOFOLLOW) < 0)
-    {
-      if (errno != ENOENT)
-        return glnx_throw_errno_prefix (error, "fstatat(%s)", path);
-      ret_exists = FALSE;
-    }
-  else
-    ret_exists = TRUE;
-
-  *out_exists = ret_exists;
-  return TRUE;
-}
-
 gboolean
 ot_openat_ignore_enoent (int dfd,
                          const char *path,

src/libotutil/ot-fs-utils.h

@@ -66,11 +66,6 @@ gboolean ot_openat_read_stream (int             dfd,
                                 GCancellable   *cancellable,
                                 GError        **error);
 
-
-gboolean ot_query_exists_at (int dfd, const char *path,
-                             gboolean *out_exists,
-                             GError **error);
-
 gboolean ot_ensure_unlinked_at (int dfd,
                                 const char *path,
                                 GError **error);